Dealing with the damage when cavity wall ties are replaced

When you have your cavity wall ties replaced, it can often leave nasty scars, so what do you do?

Wall ties hold the 2 parts of the cavity wall of your house together, but what happens when they get replaced and how do you deal with the mess it leaves behind?

How do wall ties fail?

Over time a porous wall, especially one that has driven against it by the wind, allows water into the cavity and then rusts the small metal ties which are there to hold the 2 parts of the wall together.

If they rust away and then fail, this can cause a serious lapse of structural integrity to the property itself.

When wall ties need to be replaced.

Having a wall covered in bare render on old, unpainted brick, can mean the weather repelling properties of the wall covering are not as good as when the home was built.

These types of surfaces can absorb a lot of water and damp when it rains, especially combined with a driving wind too, which literally forces the water into the walls, to cause you more issues, such as rusting your wall ties.

You can see a section of wall below which shows the metal rods which hold the brick wall (external) and the block wall (internal) together so they do not collapse in on one another. Older homes with solid walls do not have this system.

wall ties and insulation inside a cavity

The cavity acts as an air barrier supposedly making a house with thin walls, warmer inside. Most modern homes have walls like this.

What are wall ties I hear you ask?

They are small metal (usually) strips with a dip or twist in the centre, and are built into the house by the bricklayer, and bind the 2 “leaves” of a cavity wall together.

The above image shows the 2 leaves or wall sections of a house, but in this case, insulation has been added inside the cavity to give the occupants a much warmer house.

When a house is buffeted by driving rain and the water soaks into the wall, the twist in the middle of the wall tie allows the water to drip off, inside the cavity, and onto a cavity tray, which dissipates the water away from entering the inner leaf, essentially, your interior walls.

When this happens, you start to get damp in the house, which can cause all manner of problems.

So what can be done to avoid all this?

When wall ties are replaced it is often best to contact an accredited wall-tie replacement company who have the right experience and knowledge to carry out the work.

If you choose to ignore rusty wall ties, eventually the walls can start to “bow” (Bulge outwards) and then in the worst scenario, the outer part of the wall can collapse.

This is because the steel wall ties hold the 2 sections of wall together and when they rust, as is often the case with older iron ties or steel (but not stainless), the house essentially loses its tensile strength, or the ability to hold the 2 sections of wall together.

When a wall tie replacement company carry out the work, they remove and replace all the old wall ties, giving your home back it’s strength.

This is because cold weather attacks the fabric of each house, and water gets into any small cracks that may be present on the render or pebbledash, and then expands when it freezes, making the cracks EVEN WORSE and even harder to fix.

It is this freeze and thaw action during the winter months that can cause more damage to your house than you ever thought possible, and if you have not had your home protected with one of the NPA Weather protecting wall coverings, then you can be sure it has happened for the past few years to your house.

However, as far as appearance, the wall can look ruined, like this one below.

This is the mess we had to sort out when a client had cavity wall ties replaced

As you can see, there is a network of scars on the wall now, where the wall ties were replaced.

No matter how good a decorator is, you cannot apply normal masonry paint to the walls of a house like this and not expect to see the same scars grinning out through the paint.

The ONLY way to cover this effective is with the use of a textured masonry coating, which being 20 times the thickness in microns, of a normal film of paint, will cover and hide the scars, giving a pleasant and uniform wall finish.

¬†After wall tie replacement…

After they have been replaced, our teams apply our special exterior wall coatings to the house, which last up to 20 years and do not fade, crack, chip or peel and it is the best house wall painting system around.

The NPA wall coating painting system also benefits from a 20 year warranty, available direct from the contractor.

All this sounds expensive yes?


Well as we do a “holistic” exterior repair and decoration to your home, the cost comes right down as you do not have to employ several different tradespeople, just to get the place repaired and painted.

Start saving money and give us a call now.

We can be reached by dialling (0800) 970 4928

You can also send the team an email here.

Written by surveyor Guy Alexander Bell. Bsc.(hons.).Pg.Dp.

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