Decarock stone cladding and veneers are suitable for application onto concrete blocks, specialist building boards and ICF projects.
With an approximate weight of up to 60kg per square metre, any board system must be designed to suit.
We recommend using a 12mm Magply Renderpro, Knauf Aquapanel Exterior or similar, that can be used for projects which utilise steel or timber frame structures both internally and externally.
These boards can also be used to face retaining walls or existing render to create a secondary strong and lightweight surface to receive the Decarock panel system.
Decarock panels can also be applied directly to new or old concrete blocks or brickwork. When applying the panels to a concrete block substrate, the adhesive offers a full and complete bond. The Decarock Panel Adhesive has been designed to work both indoors and outdoors and when used as a full coating over the substrate at a minimum thickness of 12mm, will offer excellent weathering performance.
It is important to ensure that the Panel Adhesive is applied fully over the back of the stone and onto the wall to maximise adhesion and avoiding any air gaps.
If using Thermalite concrete blocks a slurry coat of SBR and a high polymer basecoat must be applied to prime the block beforehand. A thicker layer of Panel Adhesive would also follow.
Measuring and Ordering
Ensure you have enough tiles to cover the area you intend to clad. To do this measure the horizontal and vertical dimensions, multiply these two figures together and then add on some extra to cover wastage and cutting. We would normally say around 10%. This wastage figure is only a guide as some areas will require less and some will require more.
Check your product description as to the coverage of your panels, divide this number into your total area, this will tell you how many boxes of panels are required.
When calculating corners, measure the height of the corner in metres and divide this by 0.150 (the height of the Cladding or Veneer tile). This will give you a figure that will be the number of individual long corners and the number of individual short corners required.
Again check your product description as to how many pieces are in a box as this varies for each product. Divide this number into your total for each component, this is how many boxes of corners are required.
Remember to take the corners required from the number of panels measured earlier. Alternatively, this quantity can be used instead of the 10% wastage figure.
Don’t worry – our technical team will help you with your calculations if required.
To work out how much adhesive you need, we would normally advise allowing approx. 2.5sqm/bag coverage so divide your wall area by 2.5 and this is roughly the number of bags of adhesive you will need. Add a few bags extra to make sure you have enough.
To fit your panels, all you need are a few basic tools, safety gear and some panel adhesive to apply the tiles to the wall.
We suggest the following;
- rubber mallet
- notched trowel
- gauging trowel or similar
- soft brush
- small grinder or stone cutter
- sprit level
- paddle for a drill mixer
- face mask, goggles, gloves etc
It is important that your first course of cladding is level as it will be harder to correct errors later. Use packers to ensure a level 1st course of panels and the subsequent courses will be easier and quicker to fix. Marking the wall with horizontal line at every 2nd or 3rd course will give you something to work to as you work up the wall. This isn’t necessary if you are fixing to blockwork as you can use the mortar joints as a visual guide. This is a better option than trying to level every course with a spirit level as the uneven nature of the panels can knock the true line out.
If you find your level is dropping off, look for some panels that will allow you to bring the level up over a couple of courses. This is easier than trying to level everything in a single course although with some cutting and trimming of a few tiles this can easily be achieved very quickly.
Mixing Your Adhesive
Mix the adhesive either by hand or ideally with a paddle mixer.
Do not mix more than you can use in half an hour as the adhesive sets quite quickly.
The stiffer the mix the faster it will set. The more water you add, the slower it will set and the more time you will have to make adjustments as you go.
Once mixed, the adhesive will stick to a trowel but can be flicked off easily, remaining workable without slumping.
It is worth fixing the first row or 2 with a stiffer mix as this will set quickly and allow you to progress up the wall without slumping.
Thereafter, make the mix a bit softer and it will allow you some time to make some adjustments and tweaks as you go.
Decarock Panel Adhesive will cover approx 2-3sqm/20kg bag.
The panels can be cut using a small electric grinder or petrol stone cutting saw. Plan where each cut will be made in advance.
Do not cut each course in the same place as it may show through the final job.
By dividing the wall into 3 or 4 sections and placing the joint in alternating sections for each course, will help to lose the joints in the finished elevation.
Corners and Panels
Time spent evaluating and selecting each tile before you start is time well spent.
You will probably have some long corners, short corners and panels to complete your project. It is important to identify what is in each box before you start fixing tiles to the wall as the long corners and panels look very similar.
Separate the boxes from each other so that you can quickly select the right tile for each area. Cladding Panels, for example, have a 50mm overhang at each end, whereas Cladding Corners have a 50mm at one end and a 30mm at the other end. The difference is subtle, but important.
Check if the tiles look good together and fit well as some may work better together than others.
Check for any bumps that may throw the line out, or open up a joint.
Some quick and minor adjustments round the panel with a small grinder can make all the difference to the finished appearance and the overall speed of application but don’t get too hung up on this. Remember it is a random drystone wall effect that you are creating.
Fix the Decarock tiles to the wall, start at a corner and work towards the centre,then move to the other corner and work back to the centre again.
There will be a point where the panels meet, and you will need to cut a panel to fit. This can be done by making a straight cut or the preferred option of mimicking the Z shaped cut to hide the joint.
Use a notched trowel to spread the adhesive evenly on the wall. Ideally you are looking to create a minimum 10mm thick bed of adhesive. Only coat the wall with adhesive to a tile height plus some extra. This will minimise waste and ensure you are always fixing the tiles to fresh adhesive. Next, fully butter the back of each tile with adhesive as this will ensure that each panel has a full bond to the substrate.
Ensure that the adhesive fully coats the wall and the back of the time during installation. It is worth taking a tile or 2 back off the wall as soon as you have fixed them during installation to double check, they are fully bonded.
The adhesive does 2 jobs. Firstly, it is there to hold each individual stone to the substrate. Secondly, it provides a hydroscopic weatherproof render that will help protect the substrate from the weather.
Ensure the adhesive is applied up to the ends and edges of each panel. This ensures that the adhesive will fill the joints reducing any visible joints and improving the seamless appearance. Allow the adhesive to take up and partially set before brushing the finished wall down with a soft brush to remove any excess adhesive and to clean down the tiles as you go.
Once you have fixed a row and you are happy with it, run a trowel along the top of the tiles to remove any excess adhesive from the substrate and to also close the top edge of the tile with adhesive. This will reduce wastage and the likelihood of any moisture running down the back of the tiles leading to potential delamination in the future.
Push the panel firmly into place (using a rubber mallet if required) and ensure a tight fit against the neighbouring tile. Remember to allow the interlocking edge of a corner tile to overhang the corner.
Repeat on the other side of the corner interlocking the tiles to make a good join. Complete the corners at either end of the course before working to the centre to ensure that any cut edges are hidden and distributed randomly across the width of the wall.
Points to Note
The boxes will probably have loose pieces in them when you open them as the tiles are fragile during transportation and prior to installation. This is not an issue, damage or a product failure. All you need to do is keep the loose pieces together with the tile so they can be reassembled during installation.
The tiles do not fit perfectly together. They are designed to create a random drystone walling effect and care and attention taken during installation will ensure you achieve the desired effect. If every tile offered a perfect fit then you would see the joints in the finished project.
Up to 30sqm of Decarock Cladding can be installed by one person in a day compared with up to 3sqm of rubble walling so preparation is key.
The more time spent working out corners and joints the better the finished job will be. Taking the time to look and plan ahead, rather than just getting the job finished always leaves a better finish.