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.

Enhance your property by laying a new patio – part #3

New drainage pipe for channel drain

Round by the garage and the back door of the property the wall of the garage is built into the bank of the house next door. The gravel boards of the boundary fence also act as a retaining wall holding the earth back. Rainwater runoff from higher up the road runs into the patio area of the house and makes the external walls wet when it rains hard. There is a Damp Proof Course (DPC) which prevents water penetrating internally.

To alleviate the effects of the surface rainwater run off a channel drain will be installed against the kitchen wall and continued round at the bottom of the patio running parallel with a new retaining wall which will hold back the earth from the garden. The retaining wall is made of new sleepers of lengths 1.2 metres and 1.8 metres and widths 100mm x 150mm. A narrow trench was dug and filled with type 1 with a sand and cement base that the first lot of sleepers were laid on with haunching (cement support) applied to the back of the sleeper wall once the wall was finished.

Type 1 and cement base for sleeper wall
Type 1 and cement base for sleeper wall

The sleepers were staggered to match the height of the earth that would be retained behind the wall. They were cut and offered up dry to start with to make sure they fitted together properly. Holes were drilled in the sleepers to accept 1.2 metre long 20mm steel rods which were passed through the sleepers and hammered into the ground with 2 part polyester resin being used to glue the rods inside the sleepers. The sleepers were also glued in place with a quick setting Silyl Modified Polymer glue.

Sleeper wall partially built
Sleeper wall partially built

Once the wall was complete it was left for 24 hours to allow the adhesives to set properly.

Sleeper wall finished
Sleeper wall finished

The rainwater which comes off the garage roof is carried away by a gutter into a downpipe. An inspection pit was dug following the line of the downpipe from the gutter in order to trace where the water was draining to.

Inspection pit to reveal drainage pipe leading to soakaway
Inspection pit to reveal drainage pipe leading to soakaway. Main main foul water sewer pipe routed above.

The downpipe exited into a 110mm 90 degree bend by means of a flexible reducer pushed over the pvc pipe. The inspection pit revealed that the pipe went under the shared services foul water drainage pipe and continued into a soakaway. A trench was dug to run the pipe which would be teed off and run up to the channel drain.

Inspection pit to reveal drainage pipe leading to soakaway
Inspection pit to reveal drainage pipe leading to soakaway. Main main foul water sewer pipe routed above.

In order to carry away the water from the new channel drain it was proposed that the rainwater drainage pipe for the garage roof gutter would have a tee placed into it and a new trench would be dug for a pipe to be laid and run upto a P trap. The use of a P trap was just to stop any possible gases coming up from the soakaway and exiting into the atmosphere at ground level through the channel drain. The P trap would have a downpipe that joans the bottom of the corner joint of the channel drain. Here the pipe is cut to accept the slip coupling and double socket branch.

Pipe cut ready to fit slip coupling
Pipe cut ready to fit slip coupling

Then the slip coupling is inserted with pipe lubricant …

Fitting slip coupling
Fitting slip coupling with joint lubricant to aid movement of coupling up and down pipe.

… and the double socket branch is inserted into the pipe.

Double socket branch tee fitting
Double socket branch tee fitted to facilitate installation of drainage pipe to channel drain.

Then a piece of straight pipe was inserted into the double socket outlet and 90 degree adjustable double socket bend was inserted into that which allowed a long piece of pipe to be run upto a 15 degree bend and into the P trap. The P trap was placed on type 1 and then a piece of broken patio slab to give a firm base. Once the P trap outlet was judged to be in the correct place to accept the channel drain outlet 10mm pea shingle gravel was shovelled into the trench to backfill the space around the pipes.

Trench backfilled with 10mm gravel pea shingle
Trench backfilled with 10mm gravel pea shingle

Enhance your property by laying a new patio – part #2

subbase collapse under patio

This is part 2 of the patio replacement project which we are starting for the summer. We have pulled up the old patio slabs revealing the thin sand base layer that the original house builders put down.

A pickaxe is useful for levering up the old slabs and breaking up the ground while an electric breaker is useful for any concreted areas.

Be careful when pulling up the slabs and using hand tools like a pickaxe or shovel or power tools such as a breaker to remove earth that you do not damage any underground services like water supply or waste pipes. It’s always a good idea to know where the services run and how close to the surface they are when digging out spoil.

Here you can see a drainpipe which is quite close to the surface where it exits the down pipe.

Be aware of existing service pipes
Be aware of existing service pipes

Round by the rear of the garage the slabs had sunken quite badly where they butted up to the garage wall. This was most prominent near the rain gutter down pipe which could highlight that there is a leak in the pipe below ground level which is washing out the substrate causing the slabs to sink.

To investigate this a large trench was dug in order to find out the state of the pipework.  A visual inspection revealed the pipework looked undamaged and pouring some water into the gutter showed that there were no leaks.

What digging down did reveal was that the garage had been built using a block and beam construction and the void under the floor had been left open underneath the outer most precast beam. Because the garage is single skin the wall had been built on top of the beam which meant there was no outer facing brickwork laid down to the concrete foundation footing level and therefore the void was open allowing the collapse of the patio substrate into the void.

Patio sub-base collapsed into block and beam void
Patio sub-base collapsed into block and beam void

In order to remedy this some pressure battens were glued to the brick and block piers and pressure treated gravel boards were screwed onto the battens underneath the outer most beam. This will stop the hardcore and type 1 that we put back into the trench from collapsing into the void underneath the block and beam garage floor.

Shuttering to block and beam void
Shuttering to block and beam void

Then the trench was back filled with pea shingle, hardcore and sharp sand.

Back fill of pea shingle, hardcore and sand put back in service trench
Back fill of pea shingle, hardcore and sand put back in service trench

Once the slabs had been pulled up and removed the next step was to workout how much spoil to remove in order to get the correct fall on the patio. This was done using a long spirit level and some stakes banged into the ground to mark the level of the top of the slab that would allow a fall of between 25mm per metre and 25mm per 2 metres. Then dig out enough of the ground to allow the required 100mm of type 1, 50mm of mortar and then the thickness of the slab.

Enhance your property by laying a new patio – part #1

Old uneven patio

Now that the summer is fast approaching it is time to start thinking about your outside spaces. This patio is twenty years old and is beginning to show its age. The patio slabs have sunken in places and have become uneven in high traffic areas. It’s time to pull up the old pavers and lay down a new patio.

When the original house builders laid the patio they put down a very thin sub base of hardcore and then laid a thin layer of sand on top without compacting the earth underneath. This has led to the slabs sinking and becoming uneven in places. See the picture below.

The first part of the project is to pull the slabs up and prepare the groundwork. This will involve taking off the old sand base layer and digging out the hardcore sub base and some of the earth below that to give enough depth for the sub base, base and slab layers. This will allow for a new sub base of 100mm of sub base Type 1 MoT. MoT stands for Ministry of Transport which is the specification for the type of hardcore used for sub base layers also known as DoT or Department of Transport. On top of the Type 1 will go a base layer of cement to a depth of 40mm. The base layer will be made up of 3 parts sharp sand and one part cement with the slabs being laid on top of the base layer. The depth of the slab should be taken into account as well to allow for a gap of 50mm if possible below the level of the damp proof course (DPC) so that the risk of water penetration into the brickwork from the splash back of droplets against the wall when it rains is minimised.

Roof Repair Case Study – Broken Roof Tile and Rotten Fascia

Repair broken roof tile and rotten fasci and box end

Roof Repair – Broken roof tile leading to a rotten fascia and box end

One of the roof the tiles was cracked all the way down the centre of the tile. The tile in question was fitted on the gable end of the house in the bottom row and had been notched out by the builders to fit round the brickwork. The cut had been made by an angle grinder and in making the cut it looks like the tile had been split in half but used anyway. This meant rain water had been running down through the split and slowly rotting away the fascia (although on the gable end it would normally be a barge board this was horizontal from the return around the eves overhang so therefore a fascia), box end and the end of one of the eves.

After some phoning around and investigation on google the tile was identified as a concrete Marley Bold Roll tile which Marley stopped manufacturing sometime around 2007. A call to a few reclamation yards turned up a good supply in a company down near Braintree.

If the property was built around or before 2000 then take care to inspect the soffits and also undercloaking (thin board used between the roof tile and facias or barge boards on the bottom row of roof tiles). If you are unsure and suspect asbestos, then it’s definitely worth getting it checked out. Have a look online. There are companies which will come out to take a sample and do a 48 hour turn around on the analysis and give you advice on how to proceed for around £150.

Broken Marley Bold Roll Roof Tile
Broken Marley Bold Roll Roof Tile

Stage 1 – Remove broken roof tile

A solid standoff on the ladder makes a good platform to hold the tools and materials while working. Always take care to follow ladder safety and make sure that the ladder is on level ground and do not overreach.

First off the gutter that was attached to the fascia had to be removed. This can be slightly tricky with older plastic guttering that has gone hard and brittle due to the elements. Try sliding the guttering back and forth in the clips being careful not to upset the rest of the run and then pull the clips out and up pushing the guttering inwards to release it. The gutter will have to be removed all the way up to the first joint beyond the fascia to be replaced. The gutter is usually joined by a slide out rubber seal. Once the guttering is off unscrew the clips and keep them safe for when it comes time to put the gutter back up.

Use a claw hammer or crow bar to lift up the tiles above and around the broken one. If any of the tiles being removed or lifted up are at the edge of the gable end then the cement between the undercloaking and tile will need to be carefully knocked out. The bottom row of roof tiles is normally nailed to the roof batten. Try and get the claw of the crow bar underneath the clout nail to lever it up in order to pull the broken tile out. If you can’t get purchase on the nail, then carefully try levering the tile up under the nail and then when slightly raised the nail can be knocked out with a thin metal bar. Slide the roof tile out. Depending on how much the tile above the one to be removed is raised up by will determine how easily the batten lugs, if any, of the tile to be removed will slide over the batten. The tile may have to be jiggled around a bit to pull it out.

Rotten Fascia and Box End
Rotten Fascia and Box End

Stage 2 – Remove rotten fascia and box end

After enough tiles have been removed to gain access to the part of the rotten fascia being replaced pull back the felt (sometimes the overlapping felt has rotted away) and remove any undercloaking if any. A cordless reciprocating saw was used to place a mitre cut just beyond the rotten part of the fascia, taking care not to saw through the soffit vent, in order for them to be removed after the nails holding the soffit vent to the facia were removed. In this case the box end had to be removed as well as it too was rotten. It was nailed to the rotten barge board through a 45 degree mitre joint.

The ends of the eves that had gone rotten were cleaned up and sealed with a timber treatment. The felt was replaced with enough left to overlap between the new fascia and gutter when replaced and then stuck down with roofing felt adhesive to make the joint water tight.

New fascia and box end cut from pressure treated timber
New fascia and box end cut from pressure treated timber

Stage 3 – Make new fascia and box end

The new fascia and box end were cut out of pressure treated timber and painted with 2 coats of exterior white gloss paint. They were offered up into position and then holes were drilled to allow the box end and new facia to be screwed together and the new fascia to be screwed to the old fascia. The soffit vent was tacked back into position on the fascia. The screw heads and mitre joints were filled with exterior repair filler and painted over.

Replacement Marley Bold Roll Roof Tile with notch cut out
Replacement Marley Bold Roll Roof Tile with notch cut out

Stage 4 – Cut a notch out of the replacement roof tile and put back

Now was time to cut the notch out of the replacement Marley Bold Roll tile using an angle grinder taking care to wear protective ear defenders and eye protection. The tile was offered up to make sure it fitted. Happy with the fit of the replacement tile the rest of the tiles were put back wit a bead of an MS Polymer exterior adhesive was placed down the edges of the tile that will be in contact with the roofing batten and the felt. This was because it is difficult to get the clout nails back into the tile nail holes without damaging the tiles around it particularly if close to tiles near the hip, valley or gable end of the roof. Then using the same procedure as removal the tiles were put back by placing a claw hammer under the existing tiles to allow the tiles to be slid in and interlocked, taking care to get the batten lug over the batten.

The last tile which in this case was the replacement tile with the notch cut out was put back having had the fibre cement undercloak nailed back on to the top of the new replaced box end first and a bed of exterior repair cement laid on top that the replacement tile would bed into.

The last job was to screw the gutter clips back on to the facia and put the gutter back up making sure the fall was in the right direction to allow the rain water to drain away.

 

Renovate your favourite old chair

Do you have a favourite leather or vinyl sofa in your house or perhaps chairs at your office or in a salon that are beginning to show their age or have become discoloured in the line of duty. As long as the fabric is structurally still sound then a rejuvenation of the colour is not as problematic as it may seem at first glance. Even if there are minor blemishes in the material then these can also be improved and sometimes eradicated completely.

It is important that the fabric be as clean as possible so as to give the leather and vinyl colorant dyes the best chance to penetrate into and adhere to the fabric. In order to achieve this first of all give the material a good clean with a foaming interior cleaning agent using a sponge and then plenty of soap and water then use a good isopropyl rubbing alcohol with a high alcohol percentage to get all the grease and dirt off of the fabric and to evaporate thoroughly in order not to leave any cleaning residue behind that may impede the application of the colour dye and paint.

Minor blemishes like a small cut or burn marks in the fabric can be repaired with special leather and leatherette colourant dyes that are quite thick in viscosity. They can be painted into cuts and burn marks in order to fill the gap and smooth out the blemishes. The dyes can be applied in layers to build up the necessary thickness and are available in a range of colours to suit your requirement.

With all the blemishes in the fabric repaired now the material can be repainted to either restore its original colour or to change the colour to a new one. Use an all surface spray paint that can be bought from your local hardware store. Spray outside and be mindful of where the overspray will go. Make sure you wear a face mask, eye protection and gloves. Give the can a good shake for a minute or so before you spray and use even strokes across the surface. Do not allow the spray to become to thick in one place or it will produce runs. Build up the finish in layers allowing 20 minutes per layer for the paint to become touch dry.

Once the painting is complete allow to dry thoroughly for 72 hours before using your newly restored chair again.

Make Your House Entrance Hall Pop With An Engineered Oak Wood Floor

Finally The Engineered Oak Floor Is Complete

The entrance hall is the first thing that everyone sees when they step into to your property. One of the easiest ways to give your house an upgraded hallway is to put down a gorgeous engineered oak floor to really make it stand out.

First job is to remove all the old carpet and underlay along with the gripper rods and door threshold bars. Then all the skirting boards were removed. These were a little tricky to remove because they had been nailed through the dry wall and into the thermalite blocks as well as being dot and dabbed but prizing them off the wall using a wall paper scraper, claw hammer and cold chisel did the job. Then  the walls were filed, sanded down and repainted.

Removing Old Carpet, Underlay and Skirting Boards
Removing Old Carpet, Underlay and Skirting Boards

We did a moisture check on the concrete screeded floor and found that the reading was around 3 to 4 percent which is a little on the high side when laying wooden floors. To minimise the amount of water that could permeate through to the engineered boards we decided to apply a rapid drying liquid damp proof membrane (DPM). We painted this on using a large brush and allowed an hour between coats and then let it totally dry for 24 hours.

3 Layers of Rapid Liquid Damp Proof Membrane Being Applied
3 Layers of Rapid Liquid Damp Proof Membrane Being Applied

Now it was time to start laying the hand beveled oak smoked engineered boards. The width of the first board was calculated to allow the width of the last board on the opposite side to be a similar width. The boards were laid in a randomised staggered pattern so as not to have any uniformity where the joints were made. A gap of 10mm was left between the dry wall and the edge of the board to allow for some expansion. An MS Polymer adhesive was used to glue the boards down with the first row being weighted down and allowed to dry before the rest of the boards were laid. The boards have a tongue and groove joint which was tapped into place with a rubber mallet and block of wood to protect the face of the boards. To apply the adhesive to the floor a 10mm v notched trowel was used to spread the glue after it was poored on the screed. A chop saw with an fine 80 tooth blade was used to cut the boards. But none of the cut ends are on show as they are all hidden under the thresholds.

The Engineered Oak Dark Smoked Hand Beveled Brushed & UV Oiled Boards Being Glued To The Substrate With a MS Polymer Adhesive
The Engineered Oak Dark Smoked Hand Beveled Brushed & UV Oiled Boards Being Glued To The Substrate With a MS Polymer Adhesive

A multitool was used to cut the architraves at the bottom of the door frames to allow the boards to be slid in underneath.

The Floor Boards Being Fitted Under The Door Frames and Architraves
The Floor Boards Being Fitted Under The Door Frames and Architraves

Once all the boards were laid the the skirting boards were glued back on to the dry wall. Skirting was added around the newel posts and gap filler was run around the top of the newly applied skirting.

The Solid Oak Thresholds Being Fitted Between The Room Junctions
The Solid Oak Thresholds Being Fitted Between The Room Junctions

Then solid oak thresholds were added underneath the door stops to finish off the junctions between the cloak room, living room and kitchen.

 

Fixing to Breeze Blocks Using Chemical Fixings

Using chemical to fixings in thermalite blocks

Breeze blocks like Thermalite or Celcon are used a lot in the property industry for their ease of use and green credentials. We had a requirement to fix some wall brackets to Thermalite blocks.

The fixings needed to be able to with stand a reasonable amount of weight being hung off them so had to have good structural strength. Thermalite blocks are scratched with a series of lines which indicate the type of block. In this instance the blocks had 6 squiggly scratch marks that designate the fact that they are from the “Turbo” range.

Thermalite blocks are quite brittle and can be easily drilled or cut producing alot of dust when worked. Any fixing into the block needs to create a tight and secure bond with the inside of the drill hole.

The fixings used here contain chemicals so where gloves, eye protection and a mask in order to minimise  accidental ingestion or contamination.

This job requires M8 studs so a 10mm hole is drilled into the Thermalite block using an HSS drill bit to a depth of 85mm.

Holes drilled ready to accept chemical fixings
Holes drilled ready to accept chemical fixings

The holes need to be thoroughly cleaned out of all dust created from being drilled. To do this a straw, preferably a metal one to stop the straw walls from collapsing under pressure, was taped to the nozzle of a vacuum cleaner and inserted into the hole with the vacuum cleaner turned on to suck out all the dust. As a belt and braces exercise the inside of the holes was coated with a very quick drying clear concrete sealer and left to dry for 4 hours. This step is not absolutely required.

Using a vacuum cleaner with a straw attached to clean out the dust made from holes drilled in thermalite blocks for chemical fixings
Using a vacuum cleaner with a straw attached to clean out the dust made from holes drilled in thermalite blocks for chemical fixings

With the holes prepped to accept the chemical fixings its now time to insert the glass capsules. Make sure the arrow on the capsule is pointing into the hole and push the capsule all the way down to the bottom.

Inserting the chemical fixing capsule into the hole following the direction of the arrow printed on the glass
Inserting the chemical fixing capsule into the hole following the direction of the arrow printed on the glass

Then place the hex end of the M8 stud into the chuck of a drill and tighten it up. Place the chisel end into the hole up against the end of the glass capsule and start the drill pushing the stud into the capsule until it breaks.

The threaded stud is placed in a drill and pushed and drilled into the chemical capsule
The threaded stud is placed in a drill and pushed and drilled into the chemical capsule

Drill the stud home so that the collar of the stud is just protruding out of the hole and then leave it to set for an hour.

Threaded stud drilled into the chemical capsule and left to set
Threaded stud drilled into the chemical capsule and left to set

Once the chemical fixing has been allowed to set the bracket can be mounted on the studs and the hex nuts tightened up to secure it.

Wall bracket mounted to studs using chemical fixings
Wall bracket mounted to studs using chemical fixings