How Do I Paint Exterior Masonry?

When you look to paint or refresh the external masonry on a house or building there are 2 things that will be achieved - the exterior will look revitalised and aesthetically pleasing, but also it will be protected from certain environmental elements.

Preparing masonry walls before painting

Preparation and planning before painting give you the best chance at achieving the required finish. External surfaces are rarely ready to be painted straight away; uneven areas, cracks or holes are all likely to be present and need to be tackled and prepped before you start applying paint. You should look to remove any loose or flaking paint, starting with a wire brush and then wash down to clean grime and smaller dust particles left behind.

Filling:

Before you start painting the outside masonry, you should fill any holes to the exterior using a good external filler. Take your time doing this so that you can ensure a good finish. It is worth noting that the filling used for any cracks and holes will usually shrink by the end of the preparation period. To compensate for this shrinkage, you will need to overfill the gaps with the materials. 

Smoothing and sanding:

There are a couple of instances where you may need to sand back, for a good finish. If you have had to overfill and holes or cracks, it’s likely that you will need to sand the excess back to give a level and smooth surface. Similarly, if there are any small areas that have cracked, you may be able to sand these down to leave a smooth finish.

Start with the coarser grain sandpaper (80 - 180 grit) and if you find small areas that are cracking, you can simply sand them back. You can then use a finer grit to give a smoother finish and seal.

Cleaning

If you find there are any mould growths present, these should be treated with surface cleaners. Ensure the mould had been completely removed and the area dry and clean before considering painting.

Priming

If you are working on a wall that has never been painted before, you will have to apply a priming coat

1. Hydrosol Masonry Primer

Topcoat Options

1. Finngard Silicone Protect
2. Finngard Opaque (High-performance option)
3. Hydroblock WB  (Clear protection). Note, no primer is required before application of Hydroblock WB

You should expect to use at least two coats of paint. If the wall was previously painted, one layer of masonry paint may suffice.

If you require more advice on painting over lead, give our technical team a call on 0131 334 4999 or send them a message here.