Porous gable advise

Poe · 25 Feb 2020

Hi all,
The gable end of my property is fully exposed to driven rain located on a hill and water literally pours in to the cavity.
I repointed from the top to half way down last year and hoped to finish this spring but there isn't any point as I have been removing the chimney in the loft so have had the cavity expose and almost as soon as it would start to rain I could watch the water running in.
So what do I do.

Most people have said just render it which most houses here have been but I also see most are cracking and most likely holding moisture and damp in.

I could clad it but I find a full gable end cladded would look cheap and nasty and I couldn't afford the expensive stuff.

Or I could apply a sealer/waterproofer which is the idea I like the best I don't seem to be able to find anyone who has had a similar issue and used it. Also with how bad the rain is driven in would it cope.

The other issue with sealer is if it didn't work well and I ended up deciding to render I would guess the render would then struggle to bond properly.

A bit of advice would be great,

Poe.

plastic_peanut · 25 Feb 2020

I would go for the sealer if this is your preference. Plenty of YouTube videos to demonstrate their performance.

If it doesn’t give the smdesired effect there should be no issue with rendering at a later date. The wall can be coated with SBR prior to rendering

Poe · 26 Feb 2020

The only videos I can find don't show any images of the sealer performing in driving rain conditions and/or footage from inside the cavity.
Water beading off the brick face is one thing but water soaking and being pushed through the mortar is another.
I would also think that trying to apply mortar afterward would lead to issues.
Has anyone used these sealers and what results did you get?
Anyone advise with other options.
Cheers Poe.

Notch7 · 26 Feb 2020

you need a silane / siloxane based sealer

there are various brands, Ive only used a SIKA that was good and also I have bought damp proofing products from safeguard and promain and can recommend them both

stormdry masony cream:

https://www.amazon.co.uk/Stormdry-M...locphy=9045866&hvtargid=pla-697073001333&th=1

sika
https://www.promain.co.uk/interior-...t/clear-sealants/sikagard-700-s-aquastop.html

there are other cheaper ones on the market, but I cant advise whether or which are the best. I do know however that silane and siloxane based products are professional sealers, wheras silicone based ones like thompsons seal are DIY use. Silicone doesnt penetrate the same and doesnt last as long.

KenGMac · 26 Feb 2020

What ever you opt to use, ensure it is a "breathable" material, if not? it can trap moisture in the already saturated brick, much as you describe when applied render is seen to crack in adjacent properties.

Poe · 27 Feb 2020

Thanks guys,
I'll have a good look at some products and hopefully be able to find something that'll work.
Cheers,
Poe.

KenGMac · 28 Feb 2020

Poe, good evening.

OK Obvious but? suggest you suffer the effects that are on-going at present.

Wait to apply the product of preference until mid / late Summer [if we have one??] to allow dry weather and sun + wind to assist in drying out the brick work and hopefully trap as little moisture as possible?

Brigadier · 28 Feb 2020

KenGMac said:
Poe, good evening.

OK Obvious but? suggest you suffer the effects that are on-going at present.

Wait to apply the product of preference until mid / late Summer [if we have one??] to allow dry weather and sun + wind to assist in drying out the brick work and hopefully trap as little moisture as possible?

Would a breathable render not allow any moisture to (eventually) escape anyway?
Not being snotty, genuinely interested for my own house.

gasbanni · 2 Mar 2020

Whatever you do do not render it ! Moisture can be drawn in by capillary action through microscopic cracks and then cannot evaporate and dry out through the impermeable render.
Are you sure it's not a roof problem ? What kind of verges do you have ?

You could just roller on a sika product as already mentioned such as sikalastic -625
It looks like paint but the most important thing is its water vapour permeable so your wall will dry out.
Don't be fooled by claims of microporous products it's not a real term.
Some of the sikalastic products last for years don't think of them as 'paint'

You could slate the wall used to be done a lot in the past on gable end walls in sunny Lancashire.

Or you could go the old fashioned route of roughcast https://www.buildingconservation.com/articles/lime-harling/lime-harling.htm

Unlike cement render it absorbs water and then water freely evaporates through it good weather.
You could even lime wash it ! https://www.spab.org.uk/advice/limewash
Anyway don't render it and don't paint it with masonry pain !!!!!!

Poe · 25 Mar 2020

Sorry guys only just seen these last few replies,
Gasbanni it's definitely not the roof I fully repaired both sides 2 meters from the verges inwards and removed the chimney stack all this can be seen to be effective.
You can actually see the water coming in through the brick work and mortar inside the cavity (as it's exposed currently from where the chimney was removed).
KenGMac yeah I'm still waiting for a long dry spell before ANY work is done.
I never really wanted to render due to the problems associated with it and as suggested about.
I'm still considering the products mentioned and will try to remember to come back next winter to let people know how successfully it was and what I used.
Many thanks to you all.
Poe.

Porous gable advise

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