Water Seal is the product rubbish, or is it something I did?

[stem]

Four years ago, I had a nice new brick wall built at the front of my house. Being conscious of similar walls that were around my neighbours homes, I noticed that they had suffered frost damage.

To prevent mine suffering the same fate, I purchased some of this Water Seal and applied two coats the first summer and another two coats the following year. By then, the tin was empty and was happy in the knowledge that my wall was well protected. I was therefore shocked yesterday to notice that about 5mm of the facing on two of the bricks has blown off, with the remaining brick covered in ice. The top layer of the wall is constructed from engineering bricks which is fine. It's a double brick wall, and the Water Seal was applied to both sides and the top. It seemed to soak in well at the time.

So is the product rubbish, or have I done something wrong when applying it? I waited a few months after the wall was built for the initial application, which was in May and there hadn't been any significant rain for two weeks.

So after the damaged bricks are replaced, I will need to apply something else, anyone make a recommendation?

 

[Hpd]

I can't make a recommendation but I've also used water seal on some repaired concrete sills, these also ended up cracking due to frost so I question how good that product might be.

 

[^woody^]

The product is not rubbish, nor have you likely done anything wrong. It is however unsuitable for what you wanted to achieve

Water seal will not protect from frost. It is surface water repellent, not water proofer.

You need to select suitable bricks

 

[stem]

Thanks woody

To be honest though I'm not completely clear, shouldn't a water repellent, erm.. repel the rain and stop it getting into the bricks. It's the water that has permeated into the bricks that has frozen and blown the facings off. The wall is not submerged and the top is protected by engineering bricks. The facings just get rain blown against them the same as a house wall. If a water repellent isn't able to keep rain off, what is the purpose of it?

I can't do much about selecting the bricks as they are already there, but could you recommend a water proofer I could use once I have replaced the blown bricks?

 

[peterperfection]

Thanks woody

To be honest though I'm not completely clear, shouldn't a water repellent, erm.. repel the rain and stop it getting into the bricks. It's the water that has permeated into the bricks that has frozen and blown the facings off. The wall is not submerged and the top is protected by engineering bricks. The facings just get rain blown against them the same as a house wall. If a water repellent isn't able to keep rain off, what is the purpose of it?

I can't do much about selecting the bricks as they are already there, but could you recommend a water proofer I could use once I have replaced the blown bricks?

Engineering bricks still have 'mortar' joints. (a chain is only as strong as its weakest link).
Fit copings to the top of the wall--that will help a lot .
(and before anyone says ''copings have joints too--Yes they do- BUT not as many).

 

[^woody^]

If a water repellent isn't able to keep rain off, what is the purpose of it?

These repellents work by repelling most surface water which is driven at the face using a sort of surface tension effect, but there comes a point where the amount of water is too much and so it will eventually soak into the pores.

It is also broken down quite quickly by UV from the sun.

Some moisture is always going to get into the wall, and this should naturally evaporate. So if the bricks are spalling from frost, then they were unsuitable in the first place - either not frost rated or a few bad bricks. It is very rare to see frost damaged bricks, and there should be no need to coat walls with anything

Labelling this product as being able to protect against frost is a half-truth.

When used on a house wall, there is some heat from the house and forced evaporation outwards, so together with surface repellency, then this will provide the frost resistance. But on a free-standing garden wall, it can never ever function as providing resistance to frost

There are other products (silane based) which work better than the silicone liquids, but again I doubt that they will protect garden walls

The only answer is suitable bricks with good quality pointing, and a coping with a drip to cast water off the face of the wall