If you think blockchain is something police throw in the road to stop criminals then read on …

What is Blockchain all about? The term ‘blockchain’ has become synonymous with cryptocurrencies like Bitcoin, but the phrase actually refers to the underlying infrastructure used to transport and store cryptocurrency transactions. When Bitcoin was developed, a secure method of storing currency and completing transactions was required, and so the blockchain process was created.

When Bitcoin was developed, they needed a method to transact and store the currency using a secure method, so they created the blockchain process.

In the bygone era of 70s and 80s computing technology, hardware was obviously much less powerful and hard disk processing much slower than it is today. To link records together we used chains of relative record numbers, or RRNs. These RRNs pointed to the previous and next records in a chain, for example adjacent rows of a file or table, or related records. Software programs could follow these chains in order to extract information. This structure of chaining records together was commonly used in back office systems like stock control, for example to allow the easy extraction of widgets, widget meaning anything that might be managed in a stock management system like items locations etc, being stored in a particular location. IBM developed an early Enterprise Resource Planning System (ERP) called MAAPICS, which stands for Manufacturing and Accounting Production Inventory Control System, and which used RRNs. RRNs were a good way of allowing the association of things together without a complex database technology under the covers. If the chains, or RRNs, were corrupted then the integrity of the data was compromised. With more modern technology came faster and bigger hard drives and faster processors. The use of complex databases allowing logical indexes became commonplace, allowing lookup by key (or number, for example widget number), or store location code thus doing away with the need to chain records together.

The concept of chains linking data together is used in blockchain, providing integrity rather than speed. Individual records, or blocks, are linked together in a chain. If the previous hash of a particular transaction does not match the value of the previous transaction then that indicates that the chain has been tampered with. The advantage of blockchain is that records of transactions are duplicated across a network of computers, so finding out the correct value is straightforward. This is where the concept of consensus comes into play. If the majority of machines share the same previous and current transaction values, then you can be confident that those values are correct.

A phrase you hear quite a bit in relation to Blockchain is “Immutable Ledger”, which sounds to me like something you would use while fly fishing in Scotland. It’s just a fancy way of saying that transactions stored in a blockchain are very hard to amend once committed to the chain (although theoretically not impossible). In financial circles a ledger is a record of financial transactions. “Immutable” is defined as unchanging, or not able to change over time. So, an Immutable Ledger is simply a record that cannot be changed.

When a blockchain transaction is processed it is duplicated across a network to many computers, which are known as nodes, or peers. A blockchain network is a peer to peer, or P2P network. The fact that the data is mirrored across multiple computers is one reason (but not the only reason) it is difficult to retrospectively amend a transaction once it has been accepted into the ledger, because it would involve making changes to the transaction records on many computers.

Transactions are added to the chain by one node in the network and are then duplicated to all the other nodes. To win the privilege of adding transactions* to the blockchain, a node must first do battle with all of the other nodes on the network. In a Bitcoin blockchain the winner is rewarded in bitcoins, or part of a bitcoin. This act of battle is called “mining”.

The battle that takes place in the mining process is actually a puzzle solving competition by all the nodes in the network to see who can solve the puzzle the quickest. This process is known as Proof of Work or PoW. To try and give themselves the best chance possible of being the first to solve the puzzle and win the mining fee the computers that do the “mining” are made to be as powerful as possible using specially made hardware. They consume quite a bit of power and some organisations have built server farms with many nodes in order to increase their chances of winning as many PoW contests as possible and therefore maximise their profit.

The process of actually adding transactions to the blockchain involves bunching individual transactions together in order to create a block. The block header contains the hash which was created in the Proof of Work process (by the winner of the mining process) and the hash from the previous block.

Because the hash of each block is built using the hash of the previous block this means that to amend transactions in any given block you would have to go back and amend all the hashes and previous hashes in every other block created before it and also on 51% of the nodes in the network to get consensus. This is what gives blockchain technology its “immutability”.

The hashes, previous and current, that we talk about that are stored in the block header are created by the PoW process as we previously discussed. A hash takes bits of information, concatenates them together and then applies an algorithm to return a fixed length string of characters that is used as a unique identifier for the block. The PoW concept comes about through adding complexity to the hash creation process by way of stipulating that the hash must begin with a certain number of zeroes. So when the hashing algorithm creates the return string if it does not begin with the required number of zeros then the process of hashing the concatenated information is retried until the number of leading noughts is realised.

The hash function is basically a mathematical equation that takes an input string of any number of characters and outputs a string of completely different characters with a fixed length. The result will always be the same for a given input string. The hash process is known as being deterministic ie the same input string will always produce the same output string but you cannot reverse engineer the output string to get back to the original input string. The hashing algorithm used in Bitcoin is SHA256. Hashing is used because it means passwords can be stored without exposing the actual password. To verify a password it is hashed and if the hash matches the stored hash then the password is correct.

Use the demo below to enter a sentence and press the “Press for Hash” button to view how the SHA256 algorithm turns your string into a fixed length set of numbers and letters.

In Bitcoin, which is stored using blockchain, the coins are transacted using “Wallet” functionality. To access the wallet private and public keys are created using what is known as Elliptic Curve Digital Signature Algorithm (ECDSA) to create hashes utilising SHA256. The owner of the wallet must keep their private key secure as this is the method by which they access their wallet and perform bitcoin transactions. People that know your public address can send you bitcoins.

Enter string:


One of the other elements that makes up the block header is a timestamp turned into a Unix Epoch time which is the time in seconds since the 1st of January 1970. Use the demo below to enter a date and time and then press the “Press for Epoch” to see your chosen date and time converted into seconds since the 1st of january 1970.

Enter date/time:

Epoch Time:

The block header is made up of the version number, previous hash, this hash, epoch time, difficulty and nonce. As mentioned previously the difficulty is thrown into the mix to make the block creation or mining process a competition to see who can find the answer first and win the privilege of creating the block and earning the mining fee. The difficulty part of the mining process stipulates how many zeros the hash must have at the beginning and is geared towards making a 10 minute gap between block creations. This is dependent on the power of the mining computers, how many of them there are and how many transactions are being processed in a period of time. A nonce is added to the end of the string being hashed to attempt to find the required number of zeros to be prefixed to the string, if the required zeros aren’t found on the hash computation then a new nonce is tried until the right amount of zeros are computed. The nonce is effectively a random number 4 characters long. To vary the complexity the number of zeros is upped or lowered accordingly. The diagram below explains the hash creation process highlighting the way the difficulty is used to build in complexity.

Hitting the button below brings up an interactive demo which models the blockchain mining process in real time.

Blockchain technology is being considered by the HM Land Registry for use with land registry transactions. In a blog HM Land Registry wrote in May of 2019 Could blockchain be the future of the property market? they outlined the steps they took to “build a prototype that would enable a digital transfer of a property that automatically updates the Land Register”. They bought together payment services firm Shieldpay, law firm Mishcon de Reya and conveyancing MyHomeMove, know your customer (KYC) and anti money laundering (AML) services provider Yoti and HM Revenue & Customs to build as they described an end-to-end proof of concept.

They used video to allow the participants to remotely interact allowing them to coordinate their various tasks. Each step was actioned and then the process was handed on to the next party in turn.

The aim of the simulated transaction was to demonstrate the speed, trust, security and transparency that the technology could bring to the property market.

In the article The Land Registry said they are continuing to work with industry to explore how new technologies like Blockhain can influence future transactions.

Smart contracts are being tested by the legal profession and by industry as a way of recording contractual agreements and storing them in a blockchain ledger. This could speed up transactional processes such as shipping contacts and documentation by allowing documents to be created , submitted and shared in a more secure and timely approach.

House Auctions: How technology is changing the industry

Most of us have a soft spot for the auction process – and with TV programmes such as “Homes Under the Hammer” beaming into our homes for years’ now, no wonder! The dusty hall, where you can eye your opponent as the auctioneer nears your top bid. The thrill of the chase and the ability to scope the competition. This is all part of the appeal.

Auction houses have a sense of excitement about them, and a lot have remained steadfastly traditional until just the last few years.

Technology has started to play a more important role in auction houses, providing the ability to bid on and buy property across the UK from wherever you are. While in the past you would need to attend an auction to secure your dream home or investment, these days you have a variety of tech-led options at every stage – from the original advertising of the auction right through to the payment for your new property.

Proptech is the way forward for buying (and selling) at auction.

Searching for the perfect property – from wherever you happen to be

Traditionally, the purchase of a property should almost always take place after the property has been viewed in the flesh. But auctions are a little different.

The advent of online searching methods means investors’ can narrow down their search quickly and view only those properties they deem as suitable. They can

grab valuable data points using online services such as:

Auction house in Wales – but you’re in Scotland?

Not only that, but easy access to information makes life easy for the pre-auction investor property buyer – especially if they live in a different country within the UK!

Nowadays you can send and receive email from your solicitor – you can even FaceTime them.

Plus, auction house apps and websites now provide the ability to download seller and legal packs, immediately.

Bidding online

Can’t get to an auction? No problem – welcome to electronic bidding and online auctions. A lot of auction houses will now offer an online option either instead of or alongside their live auctions.

The great advantage of an online auction is that much of the time, you may be able to bid in advance from the comfort of your armchair without having to travel to a live auction.

You may also be able to watch the sale on a live stream, and you often have the option of setting your bidding limit. That might take away some of the fun … but you will appreciate it.

REMINDER: As auction houses sometimes only release details about the properties coming up at auction a matter of weeks before the actual auction event, this gives the auction a very short shelf life. This means that all the due diligence from your side of things must be done quickly and efficiently.

The whole process is smoother and easier

From electronic payment methods, through to online solicitors, legal packs and even mortgage offers, there are now specific financial technology (fintech) products aimed at the property auction market – enabling a quicker and more targeted response to the auction buying process. Every part of the auction property buying process is faster and smoother due to technology.

You can use your auction app to register and bid, chat on a forum with other investors to get great tips, explore the property and the surrounding area with Google maps, find online images from websites like PropertyAuctionAction.co.uk and Rightmove and discover auctions near you with aggregate auction house sites.

Technology just makes things better, and auctions are no exception.

Tech and compliance

Speaking to Max Mason head of online-only property auction house 574.co.uk, he says the main uses for technology in the property auction space right now and for the foreseeable future will be around compliance (AML- anti-money laundering and KYC – know your customer) and using data.

In terms of compliance, he wants to see the HMRC issue more clear guidelines so the industry can respond and implement a standard code of practice.  This could then open the door for more fintech based AML uses such as geo location, and biometric checks which provide a greater level of security. 

For data, Mason says this will allow the company to use its predictive AI tool to better understand and predict the outcomes before an auction happens and how likely a lot is to sell ahead of time.  This is still in its early stages. But with more data, comes more learning for the tool, which will improve its accuracy.

Tech and data

Richard Adamson, Partner and Auctioneer at Allsop explains that they have recently revamped their website and web app to better use existing technology that might seem old hat in other industries:  “This has meant we have much more data on the types of people at auctions and where the interest is.  We have also widened this appeal and made legal packs and more detail property information available online and in the app.” 

He added: “We’ve seen a three-fold increase in the number of people requesting property info via the app versus requesting hard copy catalogues. So, we’ve got 6,000 people using the app compared to 2,000 requesting hard copy catalogues.

“For the property auction space, we are at the cutting edge of what can be done and what the market can tolerate. We don’t feel the space is ready to embrace blockchain or other technology for the sake of it. If it isn’t adding value to the proposition, then tech for tech sake is not something we will be investing in”.

Justin Beckwith Director of Pattinsons Auctioneers shares this view.  “We are seeing a huge uplift in online auctions and technology has allowed us to move more online. This has increased the number of auctions we can run, and also an increase in the number of bidders for each lot.”

Proptech evolving

It seems that while we see rapid development in technology across different parts of the property sector, auction houses have in recent years been playing catch-up.

From what we see in the property auction space, the technology used is helping more vendors attract more buyers, and those buyers take part in auctions using any of the four main ways (in person, post, telephone or online.)  Online is clearly the growing element, and auction houses have responded to that need.

There is still work that can be done, of course. For example, perhaps adding blockchain to the auction process to make the transaction process fully transparent and immutable.  This could mean that land registry and purchase records can be added to a blockchain process.

Blockchain could also, at some point, remove the middleman entirely from the process – we see this in other industries where technology takes the place of human governance.  We also see blockchain being further used on AML and KYC as a blockchain could allow cross-sharing and validation of clients, hence speeding up the process and reducing costs.

Garden makeover complete – A night and day video walk round the property

Garden lighting at night

These videos show the culmination of 4 months of hard work around the property – from clearing away sheds, greenhouse and decking, digging up old patio and hardcore underneath, to constructing new storm drains, digging a foot down the old grass to try and remove all the weeds, copious amount of soil and rubble removed from the area (all of which was sieved and sorted into top soil and hardcore and used back into the garden), to the filling of 4 x 12 yard skips – that got us to a blank canvas!

Then began the hard slog of putting down a new patio during two heatwaves and one period of torrential rain, grading and levelling the lawn area of the garden and building a framework around the trees on a slope and adding 3 cubic metres of premium bark nuggets – all carted from the front of the house by wheelbarrow !!

During the long days of hauling soil and slabs, it felt like the time of seeding the lawn, planning where to place plants, buying pots and painting accessories was a world away but eventually that time came, the layout planning and details of placing accessories really did feel like the icing on the cake.

From a very tired and shabby looking garden, to an area that gives the impression of space and yet privacy with a low maintenance patio and decking edged area ideal for entertaining or for just sitting on the bench with a glass of wine watching the birds make themselves at home on their new bird table.

The videos are shot during the day and evening. The first one highlights the garden lighting at night showing the deck lights used along the patio and in the bottom of the sleeper wall. Whilst illuminating the decking when dark, they are not intrusive, we also used a couple of lanterns to enhance the plants. Low voltage led lights are also used to illuminate the trees at the bottom of the garden. There is also a wall washer used to show off the brickwork. All of the lights are on timers and can also be remotely controlled from a smart phone so no need to remember to switch them on.

Would we do this again? hell yes but with our eyes open wide with the realisation of the amount of work involved, the time commitment but the knowledge that the end was well worth the effort.

Dressing the garden

Garden view from west side

We are now at the stage in our garden renovation of adding plants and garden accessories to pull together all the elements – the fun bit!

By the careful placement of plants and decorations, you can give the impression of stylish, sleek and yet homely.  We used a combination of both new and old plants, new and old pots and new and old accessories, different shades of grey and blue which contrast but still compliment.  For maintenance purposes, all the plants are evergreen (with flowers or colour) for all year round show, but the trough is our seasonal garden splash of colour, this time of the year it is full of stocks, cyclamens and dianthus, in spring we will have daffodils and tulips and then summer bedding plants.

Pernettya mucronata Evergreen Prickly Heath Berry Plant
Pernettya mucronata Evergreen Prickly Heath Berry Plant

Small compact plant with eye catching white berries, placed close to the house so can been seen through french doors but does not obstruct view to other plants.

Pernettya - Purple Berry Miniature Bush
Pernettya – Purple Berry Miniature Bush

This one is the same as above except berries are pink.  It is placed in a higher container diagonally across from white one so eyes travel along the line to encompass both colours.

Ophiopogon japonicus - Pygmaeus
Ophiopogon japonicus – Pygmaeus

On the sleeper wall we have used small grey pots to hold various alpines, the smallest one above.

Sempervivum Vicentai Gaton
Sempervivum Vicentai Gaton

The middle of the three pots on the sleeper wall, yellow flowers will appear in summer on tall stems.

Iberis Fischbeck – Perennial Candytuft
Iberis Fischbeck – Perennial Candytuft

The largest of the three pots on the sleepers, produces masses of small white flowers in spring, ideal for attracting bees into the garden.

Dryopteris Erythrosora – Japanses Rosy Buckler Fern with Vinca Minor - Periwinkle
Dryopteris Erythrosora – Japanses Rosy Buckler Fern with Vinca Minor – Periwinkle

We have placed a tall cylinder planter in the corner of the patio contained two plants, the Japanese fern is ideal to use as foliage contrast with other plants, has coppery triangular fronds when young, turning light green with mature.  To compliment the fern we have added a Periwinkle, this has small inky blue/violet flower in spring and occasionally in autumn winter – we planted ours in late September and it has not stopped flowering!

Araucaria Araucana - Monkey Puzzle tree
Araucaria Araucana – Monkey Puzzle tree

The Monkey Puzzle tree we have had for a while but it now stands out as a structural element to the edge of the patio with its sweeping arms contained in a square planter, but do not be fooled, get too close and the spikes really hurt.

Azalea tree
Azalea tree

This Azalea has been lost in the old plants for some time now but placed in a planter it show cases its autumn colours  Although not evergreen, the new buds are already showing (November) with a promise of what’s to come.  In summer a mass of coral flowers can be seen.  To draw the eye to the planter, a small sphere is used.

Planter with Olive tree, Stocks and Cyclamens
Planter with Olive tree, Stocks and Cyclamens

We have recycled our old plants, it was looking a might tired but with new lining and a few coats of “silver birch” grey paint, it looks like new.  An olive tree is placed at the side to give height and structure, the rest of the trough will be planted with seasonal bedding plants to give a splash of all year round interest.

Pittosporum Tenuifolium - Irene Paterson
Pittosporum Tenuifolium – Irene Paterson

A tall square planter is used to showcase the above, it produces dark green leaves speckled with white often tinged pink in winter.  Dark purple flowers are produced in Spring. The height of this plants ensures the eye is drawn to the rest of the garden over the sleeper wall.

Garden project – Seeding the lawn

Patio and lawn east view

With all the structural and hard landscaping complete with our garden project it is now time to tackle the lawn and turning it from a patch of brown mud into a lush green lawn.

Grass seed scattered over soil in third week of October
Grass seed scattered over soil in third week of October

The area to be seeded has been previously graded, tilled, de-stoned and then raked and rollered to form a smooth base for the grass seed to be applied. It is now just after the middle of October so getting pretty late in the year to be putting grass seed down but hopefully a few weeks of reasonably mild weather with temperatures around 7 degrees or above during the day should give the grass seed enough warmth to germinate and start to grow before the really cold winter weather starts to set in.

Two types of seed were scattered over the area to be lawned. One that was fast growing with an inhibitor to help deter the birds from eating the seed and one that would provide strong growth and a dense lawn later on. The two types of seed combined provided for a mixture of perennial ryegrass and fine fescues. Both seeds contained calcium and nitrogen to act as a feed for the lawn to help it grow in the early stages. The seed was well watered for the first few days and then it has been fairly rainy since so no more watering has been required.

Mid November new grass growth 3 weeks after being seeded
Mid November new grass growth 3 weeks after being seeded

After a couple of weeks the seed started to germinate with signs of little green shoots beginning to burst through the soil into the crips late autumn air. The weather has been reasonably kind over the past few weeks in that there have only been a couple of light frosts but nothing too cold which has given the seed a chance to get a foothold before winter. Now in the middle of November there is the beginnings of a green carpet starting to appear.

Finishing the patio and garden

Garden steep bank terracing

With the bulk of the major structural work that had to be undertaken around the property now complete it’s time to look at the parts of the garden in need of some design in order to integrate them into the overall look and feel of the landscaping performed so far.

To this end the steep bank at the bottom of the garden needed some attention to turn it from a steep and fairly dull muddy bank that was a haven for weeds and not a lot else into something that encapsulated the rest of the garden was low maintenance and cost efficient to achieve. The bank contains 5 trees which have previously been planted to give a screening effect for the houses behind. The trees are 2 Photinias’ or Red Robins, 2 Holme Oaks and one Elderberry. They take a large amount of water out of the ground in the surrounding area so nothing really grows.

In one shady corner of the bank we have planted some ferns and over the rest of the bank we have put large chunky nuggets of play bark making sure that it does not contain too many finers ie small bits of chippings and mulch that would break down too quickly. In order to stop the bark from migrating downwards terracing has been placed along the bank using gravel boards screwed to stakes banged into the ground. Be careful around roots of trees when putting stakes in. The large bark nuggets stop it from being blown away in high winds as well as aiding the retention of the bark on the steep bank and stopping it from rolling down.

The premium play bark was purchased loose from a local merchant and transported in the back of a truck and barrowed into the garden.

2 cubic metres of large chunk bark nuggets
2 cubic metres of large chunk bark nuggets

Having given the slabs a really good clean with Jet wash and then mopped it down with a solution of natural stone grout and cement remover. At this point the slabs still look very like they have a powdery residue and seem to retain dirt and dust quite readily.

Patio slabs before sealing
Patio slabs before sealing

To seal the slabs and enhance the colour bringing out the dark natural tones of the slate an impregnating sealer has been used which will be absorbed into the stone but also protect them from spillages.

Sealed patio slabs
Sealed patio slabs

Add garden lights to your patio

Garden lights installed into decking and sleeper wall

With the patio construction pretty much complete and now laid in the 3 major zones around the perimeter of the house (garage, kitchen/dining room, side return) it’s now time to start building the periphery parts of the hard landscaping.

Decorative stone was used to fill the voids around the guttering down pipes and down the gap between the paving slabs and the boundary fence that borders the side return.

Decorative stone in voids
Decorative stone in voids

With the sleeper wall already built in front of the garage patio area, to act as a retaining wall for the earth which forms the lawn part of the garden, the rest of the kitchen/dining room patio needs a boarder to edge the late slabs. To fulfil this requirement and to enhance the overall look of the garden a scheme was developed that involved laying some decking boards in two rows in front of the slabs on a wooden frame.

Frame for decking board patio edging
Frame for decking board patio edging

The frame for the decking boards was made up of 48mm x 74mm timber screwed to wooden piers that have been laid in concrete over a base of Type 1 and hardcore at 1200mm intervals. All the timber used is pressure treated and then painted with wood protection paint to extend the life of the timber. Flat timber screwed into the decking boards and laid on the patio was used to keep the frame in place while the concrete set around the wooden piers. Once the concrete had set the decking boards were screwed in place using stainless steel deck screws that would not rust and corrode over time with exposure to the elements.

Decking boards laid for patio edging
Decking boards laid for patio edging

Low voltage LED decking lights were installed in the deck boards and at the bottom of the sleeper wall.
It is also planned that spike lights will be installed under the trees at the bottom of the garden. This will help to create an inviting and chilled atmosphere for evening enjoyment in the garden.

GaGarden lights installed in sleeper wallrden lights installed in sleeper wall
Garden lights installed in sleeper wall

Enhance your property by laying a new patio – part #6

Grouting patio joints

One thing you don’t want when you’ve just grouted your patio is to have torrential rain in the next 24 hours which is exactly what we got. The grout had time to harden to a reasonable state but the excessive rain did cause what is known as effervescence where the salts bubble up to the surface and cause white staining on the grout. The grout is supposed to be a charcoal gray colour. We will have to let the grout harden fully for a few weeks and then deal with the discolouration by applying an acid effervescence cleaner to correct the problem.

Salts effervesce from grout
Salts bubble up and effervesce from grout due to heavy rain directly after application

Where the ground level had been graded and lowered below the concrete surrounding the fence posts this was structurally improved using bricks and a cement render made up of 3 parts sharp sand to I part cement and some SBR to aid the mixture sticking to the concrete.

That is the patio at the side of the house pretty much complete except for finishing and now it was time to move onto the patio round the back of the house.

The first job was to sort the frame that fits onto the foul sewer inspection chamber. This will have a slab insert in order to minimise the visual impact of the inspection chamber access cover. The inspection chamber in this instance is a Osma Drain 4D960 inspection chamber and the frame being used is a Clark Drain Recessed cover. The spigot on the Clark Drain allows for different internal diameters of inspection chamber but does not offer much adjustment up and down so the spigot from the old Osma Drain frame cover 4D961 was cut off and the first ring of the spigot from the Clark Drain was also sawn off. This allowed the spigot from the Osma Drain to fit inside the Clark Drain spigot and to be glued using PVC pipe weld adhesive giving a very strong and airtight seal and also allowing some vertical adjustment when setting the frame in place.

Spigot sawn off from Osma Inspection Chamber
Spigot sawn off from Osma Inspection Chamber
Osma Drain spogot glued into Clark Drain spigot
Osma Drain spogot glued into Clark Drain spigot

Next the riser for the inspection chamber needed to be cut down to allow for the height of the cover frame. The riser was marked round with tape to the correct height and then cut with an oscillating multitool. The burrs were cleaned up with a coarse emery cloth.
Inspection chamber riser marked ready to be cut
Inspection chamber riser marked ready to be cut

The height around the riser was built up with type 1 and tamped down then mortar was trowelled into place around the riser and the frame set in place to the correct height of the surrounding slabs and with a slight fall matching the rest of the patio. The slabs around the frame were cut using an electric tile cutter which had a water tray for the blade to suppress dust. Also water was dribbled onto the slab while it was being cut. The operators wore face guard, face mask and ear defenders. Type 1 was added around the frame and tamped down and then the slabs were set in place.
Inspection chamber access cover frame set in place
Inspection chamber access cover frame set in place

Enhance your property by laying a new patio – part #5

Slabs laid ready for grouting

With the ground levelled, falls going the right way around the property and the MoT type 1 spread over and compacted with a petrol plate the slab laying is now well under way.

Slab laying well under way
Slab laying well under way

The cement was mixed with a 4 to 1 sand to cement ratio and some plasticizer was added to aid workability and the whole mix was made up in an electric cement mixer.
Cement mixer setup under gazebo in case it rains
Cement mixer setup under gazebo in case it rains

When laying the slabs the mortar bed was built up a couple of centimetres above the height that was needed to allow for the slab to be levelled once put in place.
Cement mortar bed waiting for the slab to be laid
Cement mortar bed waiting for the slab to be laid

The slabs were set a few millimetres above the edge of the channel drain and because the slabs had a waney edge they were set back at least 10 millimetres from the drain itself.
Channel drains taped up ready for grouting
Channel drains taped up ready for grouting

A rubber mallet was used to tap the slabs down in order to level them and a spirit level was used to make sure the slab was level with the surrounding slabs and also that the fall on the slab was going in the right direction. The cement was checked to make sure that there were no voids under the slab. On the smaller slabs to borrow a phrase from the tiling world the slabs were “back buttered” with styrene butadiene copolymer or SBR for short to aid adhesion and stop them from popping up when trodden on although this will be mitigated by the grouting process.
Small slabs back buttered with SBR to aid adhesion
Small slabs back buttered with SBR to aid adhesion

Once the slabs were laid they were allowed to set for a couple of days. It was time to start the grouting process. The channel drains were taped up to protect them from the grouting process. A gunnable cement mortar grout mix was being used. The mortar being used has structural properties to give the overall patio strength once all the bedding mortar and grout have set fully after a few weeks. The mortar was mixed with the right amount of water in a bucket using a mixing paddle.
Mixing gunnable grout mortar using paddle mixer
Mixing gunnable grout mortar using paddle mixer

Once the grout mortar had been mixed properly it was placed into the mortar gun with a grout mortar piping bag having had the nozzle cut off to allow the mixture to flow easier. The mortar grout mixture in this case is fairly runny anyway and flows easily.
Grout piping bag
Using grout piping bag to fill grout gun

The grout was applied into the slab joints after well watering the joints and mopping up any standing water. The grout was allowed to set for a couple of minutes before being struck off with a grout strike. A sponge was used to wipe off the excess from the top of the slabs being careful not to rake out the grout from the joint.

Enhance your property by laying a new patio – part #4

Slate Tiles

With most of the below ground works finished it’s now time to start building the ground back up.
A green led laser level (more easily seen in daylight) was used to mark the highest point of the patio Then allowing for other factors like depth of service pipes below ground, slope of the lawn and distance of the slabs below the damp proof course (DPC) an amount of overall fall was calculated and then marked at the opposite end of the patio. In this case a fall of 40mm over 6 metres was achieved which is a little under the desirable gradient of 1 in 80.

Stakes were banged into the ground and string run between them to mark the top of the slabs from front to back. Allowing for the thickness of the slab, 40mm for the cement base and 80mm for the MoT type 1 subbase another string was run at the subbase level to show where the type 1 needed to be filled up to or ground shaved off to allow for the 80mm of type 1.

The ground was prepared with pickaxe and shovel to make it the right level for the Mot type 1. Excess spoil removed in the process was sieved through an automatic rotary soil sieve to create a pile of topsoil and another pile of stones which would be used as the first layer below the type 1 subbase. Any difficult areas of the old concrete patio base were broken up with a hex shank electric breaker using a wide flat chisel.

Once the ground was prepared the stones extracted from sieving the spoil were spread over the proposed patio area as far as they would go and then compacted using a petrol compactor plate (wacker plate). Then the rest of the required thickness was made up by the MoT type 1 and compacted using the plate.
The next step was to set the channel drain. This was installed 3mm below where the top of the patio slab would finish and laid in a bed of 4 to 1 sand and cement. End caps were put on at the highest ends using PVC pipe weld cement and the lengths were cut to clip into the 4 way corner unit which joins into the top of the soakaway pipe via the P trap through a double socket coupler joined to a piece of pipe. A gap of 10mm was left between the channel drain and the wall to allow gun injected patio mortar to be applied once the patio had been laid.

Now it was time to lay the first patio slab. The first slab required a cut to make it fit round the base of the concrete fence post. The cut was made with the combination of an angle grinder and an electric tile cutter using wet cut diamond blades. The electric tile cutter has a tray which you fill with water that the blade runs through to aid dust suppression. A facemask, face guard, protective goggles and ear defenders were used to protect the operators. Water was dribbled on to the slab while the slab was being cut to help the dust suppression process even more.

Type 1
Type 1 laid and pounded into flat surface.