Is it normal for water to leak through retaining wall and into render?

[uptown47]

Hi all,
I've had walls built in my garden and they've mostly now been rendered with K-rend.

I've noticed that I can see water coming through the render - especially seems to be tracing the pattern of the mortar (see photos)

Is this just part of the normal drying out process or is there any issue? I'm just worried that (a) it looks a bit unsightly (b) more importantly, if there's a frost will it blow the render?

The dark pattern seems to change every day which worries me that it's not drying out.

Any advice would be very much appreciated.

 

[JohnD]

If it is a retaining wall, and there is damp earth on one side of it, then the wall will be damp unless there is an impermeable layer between the earth and the wall.

 

[uptown47]

If it is a retaining wall, and there is damp earth on one side of it, then the wall will be damp unless there is an impermeable layer between the earth and the wall.

Thanks for getting back to me. The builder did make it an inner skin and I also saw some black membrane-stuff?? Is this what you mean?

 

[JohnD]

Possibly, though I can't tell if it has been fitted to entirely cover the wet face of the wall.

The black stuff might be geotextile, which is porous.

The blue stuff looks like a bag or tarp.

Drainage of the soil is also needed, usually through pipes near the base. The wall will still be damp at the bottom through damp rising g up the foundations, but not so wet.

How long ago was ut built?

 

[uptown47]

Possibly, though I can't tell if it has been fitted to entirely cover the wet face of the wall.

The black stuff might be geotextile, which is porous.

The blue stuff looks like a bag or tarp.

Drainage of the soil is also needed, usually through pipes near the base. The wall will still be damp at the bottom through damp rising g up the foundations, but not so wet.

How long ago was ut built?

The walls were built just before Christmas. There are pipes near the base on the back wall but not on the 'planters'.

The builder put a 'cap' between the inner and outer skin of the walls to stop crap falling down the gap.

Do I need to smash that off and see if there's crap down there then? i.e. Do you think the inner/outer skins are connected by stuff which is causing the seepage?

Or could there be another reason? Like water coming in from the top of the blocks and soaking through and just popping out at different parts ??

Or maybe moisture trapped in the wall slowly coming out??

Also, would this level of moisture break the render off over time? Or is the render pretty resilient?

Thanks for all your help

 

[JohnD]

If there is a cavity between the two walls, and it is empty, water should not track across.

I think I'd start by drilling an experimental hole, maybe an inch diameter, just above ground level, in the outer skin to see if water drains out or if the cavity is full of earth or rubble. If you drill at a corner you can poke something along the cavity.

Fill the hole with crumpled aluminium can to keep mice out (steel would leave rust stains)

See if the damp reduces in dry weather.

 

[uptown47]

If there is a cavity between the two walls, and it is empty, water should not track across.

I think I'd start by drilling an experimental hole, maybe an inch diameter, just above ground level, in the outer skin to see if water drains out or if the cavity is full of earth or rubble. If you drill at a corner you can poke something along the cavity.

Fill the hole with crumpled aluminium can to keep mice out (steel would leave rust stains)

See if the damp reduces in dry weather.

So, I take it that it couldn't just be the walls "drying out". I'd rather not drill holes if I could avoid it. I could take the "cap" off (the cement that covers the inner/outer walls) and have a look down the gap. But, if there's any chance that this will just be moisture that was just trapped in the bricks and it'll settle down then I don't want to do that obviously. The damp seems to be higher up than the bottom (doesn't seem be a lot coming through at the bottom) which is confusing me?

 

[JohnD]

Replacing the capping will be harder than drilling a hole.

You can wait for a dry spell if you prefer.

 

[uptown47]

Thanks JohnD. I've since found out that it's called "Ghosting". I think I need to either get a thicker coat of render on it. Or maybe paint it with a thick breathable masonry paint but I'm going to ask the renderer about it.

Thanks for all your help with this. Much appreciated

 

[Deleted member 292770]

the black ‘membrane’ looks like weed control membrane. it wont stop moisture entering the wall and will perish . A damp proof membrane would have been better.

 

[uptown47]

the black ‘membrane’ looks like weed control membrane. it wont stop moisture entering the wall and will perish . A damp proof membrane would have been better.

Ahhh... that could be an issue then. I'm pretty sure it is the weed membrane stuff. It's got that 'hessian' type feel to it. Thanks for the help

 

[Deleted member 292770]

even if you use dpm water will enter the mortar and blockwork through the render when it rains and could take weeks to dry out.

 

[uptown47]

even if you use dpm water will enter the mortar and blockwork through the render when it rains and could take weeks to dry out.

Okay... so, what would be your recommended course of action? I was all gearing up to smash off the "top cap" (the cap that covers the partition and stops soil etc dropping in) and feeding in some proper plastic damp proof sheet?

Do you think this wouldn't help much?

My other thoughts were to use the Webersil P paint (it's K-rend) over the top of it the render to (hopefully) mask the water coming through?

Is there anything else that can be done about it?

Thanks for your help.

 

[Deleted member 292770]

the main damp area is high up suggesting it’s rain water running off the top.
There’s no drain holes at the bottom?
I’d give it a few days to see if it dries out.
Either way you can’t paint it until it’s bone dry, with the risk of it spoiling if there is moisture entering from behind.
Something else to consider is there will be vertical black staining down the wall from the grout lines between the cappings. sorry.

 

[uptown47]

the main damp area is high up suggesting it’s rain water running off the top.
There’s no drain holes at the bottom?
I’d give it a few days to see if it dries out.
Either way you can’t paint it until it’s bone dry, with the risk of it spoiling if there is moisture entering from behind.
Something else to consider is there will be vertical black staining down the wall from the grout lines between the cappings. sorry.

Thanks for that... yep, all the slabs need re-doing because the guy didn't prime them so most of them have not bonded. I noticed there wasn't a drip groove in them either. I've also read that a bead of clear silicon along the bottom can help.

My plan was to put clear silicon in the gaps to stop the grout lines dripping.

The ghosting has been there for a number of days now - although it's forecast for good weather this weekend so hoping it can bake some of the moisture out of them and then I can see (on the next rain) if it returns.

In the meantime, for my own peace of mind, I'm going to remove a bit of the 'capping' this afternoon and have a look down the gap between the partition (on one part of the wall) to just see if there is anything untoward going on.

Really hope that it doesn't need any extra work - this whole job has been a nightmare so far.

Appreciate your help / advice on this. Thanks.