Rain penetrating walls - is lime render the only solution?

[jackpoint]

This is a question from wifey.

We stripped the cr@ppy cement render from the front of the house over a year ago but this is the first time it's been subjected to really heavy driving rain - the result being very very big damp patches all over the internal walls, and not just around windows.
The mortar round the bricks is generally pretty good so it's not just that causing the problem.

I've had a feeling for a while that we would need to lime render the front of the house for both aesthetic and waterproofing reasons but wifey is keen to keep it brick so the question is...are there any suitable waterproofing solutions other than rendering. Rebuilding the house from the ground up isn't an option

Here's an older photo with most of the cement render removed. Apologies for having to look at that porch :lol:


Cheers for the help and have a great New Years!

 

[Penners]

There are so many possible explanations for the damp patches that I don't think we can guarantee to diagnose them on this forum! If I had the problem, long before considering a full re-rendering (in lime of course) I would look at the following:-

* Are you absolutely certain that all of the pointing is sound?

* Could the damp patches be related to water seepage around window or door frames - or the porch roof?

* Are there any roof leaks?

* Are all rainwater goods in a sound and clean condition?

...and so on.

 

[jackpoint]

You're on my wifes side Penners :lol:

The damp patches are large and present in all four upstairs rooms. We can't really see how downstairs has been affected as the previous owner had drylined some of the rooms.

* Are you absolutely certain that all of the pointing is sound? Not absolutely 100% sure - although it doesn't look like the downstairs lounge wall has been touched (and it's not been drylined) Repointing is on the cards for the coming year though.

* Could the damp patches be related to water seepage around window or door frames - or the porch roof? Some damp patches are undoubtedly due to leaks around unsealed window frames but others are in the middle of the walls - hence wondering if the bricks have been compromised by the previous cement render job.

* Are there any roof leaks? Maybe, but they would only be small and not all the way across the frontage.

* Are all rainwater goods in a sound and clean condition? Good enough for the most part.

So probably blaming either the bricks or the pointing.....the jury is out for the minute. May have to get the repointing done and then blast it with a jet washer to see if that solves it

 

[skier-hughes]

I wouldn't use a jet washer to test, maybe a hose!!
Our walls get really wet, outside, which gradually works it's way to inside, but then it just dries up and goes away.

 

[MatthewC]

I wouldn't worry too much - the recent weather has been really cr@ppy and the wind has been doing horrible things with the rainwater - I've only just (a few minutes ago) posted a new entry on my blog (click blue spot on right) on exactly this topic!

However, I would say that in your photo there are a few bits of poor looking pointing (e.g. above the downstairs windows) and I wonder if the render that you have left around the windows is also cement?

Have you ever been outside to look at the roof and gutters when it's raining hard? I wonder if your gutters are unable to take the volume of water that has fallen in some recent (VERY) heavy showers, and so the water just runs off the roof and over a full gutter, then down the walls. I replaced the old broken 4.5" ogee gutters with 5" half round for this very reason - it seems that very heavy showers are becoming more common these days.

 

[plasticpigeon]

I find it hard to believe that rain will penetrate through 9" of brick!!! All your bricks are headers, so I assume the wall is 9".

 

[skier-hughes]

It does, even more than 9", they just get so sodden in this really wet weather. In the summer when we have a really heavy shower it doesn't come through, as I suspect the bricks are much drier. That's why the house has to be breathable isn't it?

 

[plasticpigeon]

Yes, I'm sure that is why it has to breath as you say. Rain has never penetrated through the brick walls in my house though. A good experiment would be to chuck a brick into a bucket of water for a day or 2 and then break it in half to see how wet it is in the middle.

 

[skier-hughes]

The ones standing next to the house unused might be a good test, I'll break one open now.

 

[stuart45]

It normally gets through the joints quicker, especially the cross joints. It also depends on how well the joints were filled when first built. The cross joints and inner wall joints were often not filled properly. Less absorbent bricks tend to send more water into the joints. Known as the raincoat v overcoat effect.

 

[Penners]

A good experiment would be to chuck a brick into a bucket of water for a day or 2 and then break it in half to see how wet it is in the middle.

That's a bit extreme! Your brick-in-a-bucket is completely immersed, soaking up water on all six faces. As part of a house wall it gets nothing like that exposure to water.

 

[plasticpigeon]

I have a feeling that even under those conditions it would be dry in the middle, so it takes a situation to an extreme. I'd be interested to find out what Skier's findings are!

 

[jackpoint]

Interesting stuff guys, many thanks.

However, I would say that in your photo there are a few bits of poor looking pointing (e.g. above the downstairs windows) and I wonder if the render that you have left around the windows is also cement?

The render is gone now, and the pointing is awful above some of the downstairs windows - it just didn't penetrate here :lol:

The front of the house was sopping wet, it really took the full brunt of the weather - not sure a little extra from the gutters would have made much difference at that point, but maybe the straw that broke it...

Looking forward to anyone's brick experiments

 

[stuart45]

BRE did an experiment a few years ago with a poorly built cavity wall. A sprinkler against the wall took about 20 minutes for the water to get through the cross joints, run off the snots on to the ties and bounce to the internal wall.

 

[jackpoint]

Very interesting, ta very much

 

[Mickey]

Hi Jackpoint,

Can't offer solution but I am hoping there is one, we are in Cornwall and frankly the water penetration through our walls is horrendous, granite, killas, rubble filled walls, recently repointed in lime this summer which we hoped would cure it but it is worse!! We are hoping that repointing the worst gable on the inside and perhaps rendering it on the inside if necessary will cure the problem but I currently have three trugs, one bucket and many towels in place in our bedroom because it drips down from above the tall mullion window and hits the window sill so I have to have the curtains closed and so they get soaked as well I am losing the will to live!

Mickey

 

[jackpoint]

I'm feeling your pain Mickey:-(
We have lost a pair of curtains to the leaks. Wouldn't surprise me if we end up with more casualties.

Wifey just asked if there is some sort of temporary tracer or dye you could put on exterior wall to see where leaks are originating? Good idea but don't think there is one, although happy to be proved wrong.

This isn't a bright side but got a call from the inlaws this morning. Their bathroom ceiling just fell down due to leaky roof and it's a relatively new house so the weather is hitting us all one way or another.

Happy drippy New Year........

....... just seen part of the floor is lifting in the lounge too :lol:

 

[Mickey]

Drippy New Year indeed just looked at BBC weather and tons more heavy rain on the way for Cornwall arrgghhh re curtains in the end I bought some blackout material and just hung it up, it's sort of rubbery but dries out really quickly and ha ha once we have cured this problem I can just ditch it. Let's hope we all have some drier weather soon, even rain without the winds would be a bonus! Hope you can sort your floor out, the idiot that converted this place just stuck down chipboard in the bedrooms so that's been wet as well so probably means that the cast iron rads we've just put in will fall through at some point. Trying to stay positive is not easy at the mo!

Mickey

 

[Keithj]

We're having the same problem with our south wall. I spent some time last summer filling every little crack I could find between lime and oak, pushing the lime putty well in, covering and carbonating it, etc. Wind plus rain still came through in quantity. I've fixed up a tarpaulin now, to cover that wall, and that's stopped it, but I don't like that much as a permanent solution. Come the spring, I'll be out there with the hose to see if I can find the water path.

We'd had a similar problem with the church for the past 50+ years (PCC minutes back that far mention it). The builder doing the repairs found the cause - well, multiple causes: a gutter that didn't stretch the whole width of the roof, a roof that sloped down towards the end with the missing gutter, and a buttress directly under that roof. The water had hollowed out the top of the buttress (probably over a century or more) so it filled with water that then soaked through to the inside.

 

[jackpoint]

Our dampness is currently.........ridiculous :lol:

There is a bit of the wall at the back top of the house that has been 'clad' in slates, and I must admit I'm warming to the idea!