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How to seal masonry expansion joints

How To Seal Masonry Expansions Joints

Everything you need to know about how to seal masonry joints is on this page, from how to clean, apply and what mastic to use when sealing masonry expansion joints.

Why Should I Seal Masonry Joints?

A masonry expansion joint is put in place to allow the brickwork to expand and contract throughout the year and adapt to the constant change in weather. If there was no masonry expansion joint the bricks would get damaged because of the changing forces between the brickwork. If the masonry expansion joint is left unsealed with a flexible external sealant dirt and water can get into this gap and between the brickwork which will also damage the brickwork. It is essential that this gap gets seal.

What Do You Seal Masonry Joints With?

To seal your masonry expansion joints with flexible external silicone sealant - you’ll need the following equipment:

  • Stanley knife

  • Caulking gun

  • High quality flexible external silicone sealant 

  • Silicone smoother tool 

  • Frog tape 

  • Backing Rod

Masonry Joint Sealants 

Listed across is a range of the Masonry joint sealants you can use to seal your masonry joints, weatherproof external sealants in our store, they come in a variety of colours and sizes to meet your needs. 

What Areas Of Masonry Expansion Joints Do You Seal?

When sealing masonry joints you want to make sure you seal all of the correct areas to prevent damage to the brickwork. 

Expansion Joints -  When sealing the masonry expansion joints it is easy to tell which areas to seal, you simply seal the gap in the brickwork from the bottom to the top of the house.

How to seal masonry expansion joints step by step

How To Seal Masonry Expansions Joints

Step By Step

Once you’ve got your equipment and tools, it’s time to start sealing your masonry expansion joints.

 

Preparing the Silicone

Firstly you are going to want to find the correct flexible external sealant or from a shop. There are many good brands out there to choose from, Everbuild is a high quality brand you can use to find the correct mastic for your masonry joints. 

use your Stanley knife to cut the silicone sealant tube open. Before attaching the head or nozzle of the silicone, cut the tip as close to a 45-degree angle as possible, this will make applying it much easier and neater. Then place the silicone into the caulking gun and pull the trigger slowly until you feel a bit of resistant so that the tube is securely in the gun and will not fall out.

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Clean the surface

You need to make sure that before applying the silicone that the surface has no dust, residue, water or old silicone if reapplying. You can wipe the surface down where silicone will be applied but you need to make sure it is then dried afterwards because silicone will not bond to a wet surface.

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Apply the sealant

Firstly put the backing rod in the gap you are wanting to seal and tape the sides of the brick work to avoid the sealant to sticking to the brickwork. then get as close as possible to the edge of the area you want to seal, and then apply the silicone by pressing the caulking gun trigger. In a smooth movement, begin from one end and work you way to the other end. Do not touch the sealant once you have have applied until you have sealed the whole area. When finished Applying click the leaver on the back of the sealant gun to loosen the tube and stop sealant from oozing out the nozzle. Cover the end of the nozzle so no excess sealant spills on the floor.

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Smoothing the sealant

Now spray the sealant you have applied with water (Water helps remover the excess sealant and stops it from sticking), then grab your sealant tool. Start from one end and slowly smooth the sealant bead until it is neat and flat. Make sure you have the wonder wipes ready for when excess forms on your sealant tool, do this until the joint is sealed. Your masonry expansion joint should now be sealed properly. you may want to have a look over and run the tool over any bits and are a bit wider or need slight touching up. If there are gaps this is no problem you can re apply and start the process again in that small area. After you are happy with this peel off the tape.

Give the sealant 24 hours to cure do not run any water or disturb the sealant during this time. 

Removing Old Masonry Joint Sealant 

To remove old sealant you will need a Stanley Knife a small scraping tool, sealant remover and some sort of cloth. 

Start by running the Stanley blade down the centre of the sealant, next scrape away as much sealant as you possibly can using the scraper (be carful not to damage the brickwork whilst doing this). Apply the sealant remover to the left over bits of sealant and leave it for 15 minutes. 

Now you can rub over the sealant with a cloth and it should peel away quite easily. 

The sealant removing process is a lot more time consuming than applying sealant. Once you have finished removing all sealant you can now clean down the area and re apply.

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