Damp patch - inside wall

[dexdexter]

Hello, we have a damp patch high up on the inside of our external wall to the rear of the house. Last year is blistered and looked like a cauliflower in parts. Due to the position, I assumed it was due to the gutters above, so I had them cleared. This was about 12 months ago.

A couple of weeks ago I scraped off the paint and the surface was quite wet to the touch, I aired the room and it improved. I put a layer of filler across, and sanded down. More or less straight away it discoloured. Now we've had heavy rain, the blistering is coming back.

Looking outside, nothing looks untoward, pointing etc seems fine.

It's an old terrace house, solid brick.

Any suggestions? Leaky gutter or possibly need cleaning out again?

Looking to sell the house, so obviously need this sorting.

Thanks

 

[PrenticeBoyofDerry]

There could be a number of reasons for this, I would be checking the pointing, the guttering, the drip edge of roofing felt, the roof, any ventilation brick/voids and window seals.
A picture of the damp area and the outside wall could possibly help diagnose.

 

[dexdexter]

Thanks for the response. I've got a picture of the internal wall, how do I upload?[/img]

 

[JohnD]

stand outside during rain, see if water is hitting the wall. It can be gutters, downpipes, hopper, or defective render.

see also //www.diynot.com/forums/viewtopic.php?t=129539

 

[dexdexter]

I had the guttering fixed a couple of weeks ago, the fella said there were a few cracks. He's repaired the entire length. He also said that he'd replaced a roof tile - and the roof is in good condition.

The wall has still been wet to touch with some discolouration, as we've had a fair bit of rain. I got on the phone to the roofer. He advised it could take weeks to dry out, despite them fixing the gutter.

During heavy rain yesterday, i had a look at the outside wall. There was a patch of saturated brick. I check again this morning, and its still visibly damp on the outside

View media item 81674 View media item 81675

 

[JohnD]

I see no gutter above the wet patch.

Is it a flat roof?

 

[dexdexter]

JohnD, it's a cast gutter, almost like its recessed. It's not a flat roof.

 

[JohnD]

do you mean it is one of those awful concrete gutters built into the wall?

Is there a joint under the wet patch?

when you look at it in rain, does water spill out?

 

[dexdexter]

It's a lead box gutter - just re-read the job sheet. 'Renewing all flashing to lead box gutter'

I watched for a few minutes yesterday during the rain, but didn't see any water spilling out. Can't see a joint either.

 

[JohnD]

well, the amount of water does look like a gutter fault.

If someone can get up there with a hosepipe, you may be able to see where it's leaking.

It may be too difficult to work off a ladder, but a tower might do.

 

[dexdexter]

Okay thanks. The other option I suppose is to get the bloke that did the gutter back around again, and show him the pictures.

Thanks for the pointers mate

 

[ree]

"Renewing all flashing to lead box gutter" might mean just that: the flashings might have been renewed but the lead box gutter itself has not been touched?

Box gutters are notorious for leaking and maintenance difficulties. Typically, they have to fall in steps, and sectional lengths of lead max 1500mm to 2000mm long.
You wont see the lead gutter from below - there will be a fascia and gutter boards blinding it.

You must go into the loft and examine (as best as possible) the woodwork below the box gutter in the damp area. The "cauliflower" you mention: was that a decorative effect of the damp or did an actual projection from the plaster appear?

Your roofer must come back, he/she is now responsible, and sort out the obvious failing of the box gutter: what can be observed is fresh, not drying out, moisture.
Ask the roofer for before and after pics of any new work.

FWIW: if you post how much the roofer charged you then we will have some idea of the extent of what has been done.
Did the roofer work off a ladder or tower?

 

[dexdexter]

Ree, the roofer charged £180 for the job.

No tower was used, just ladders. The cauliflower effect was in patches, not all of the damp went this way.

So what you're saying is that if the box gutter has failed, it wouldn't matter about renewing the flashing; the problem would still occur?
I'll be making contact with them today.

Must admit, it wasn't a case if just going for one option for the work. I'd used the bloke in the past for repair work on the front guttering a couple of years back and he did a good job. He'd come recommended from a friend, so I'm surprised that this had happened, given the symptoms I'd described to him.

Re the loft access, I'd taken a look but couldn't get as close as I'd liked due to thick insulation on the floor, toward the rear of the loft.

 

[ree]

For £180 from a ladder it doesn't sound like he could have stripped back the slate or tile and supplied & renewed the lead flashing. Ask him what exactly was the failure(s) in the flashing?
Perhaps the flashing and the gutter itself both needed fixing/renewing but he only attended to the flashing - i dont know?

The gutter should be thoroughly cleaned, dried off and then examined - lead pieces must be lifted back in a search for damp/moisture underneath the lead.

If at all possible, you should get up there and see for yourself - take pics and post them.

Dont give up because of insulation difficulties in the loft - use a rake or similar to pull back the insulation, and an extension cord light for a clear view. Lie down on off-cuts of any handy boards.
There is a possibility that fungal damage is present, and if it is it must be dealt with irregardless of what happens to the box gutter investigations.
The lintel above the window frame will be wood, and its bearing end is in the damp area.

Perhaps post pics of the affected interior wall area.

 

[dexdexter]

He said before doing the work that the first row of tiles would be lifted and flashing would be renewed. He said the issue was cracks along the length. I don't think the box gutter itself was closely inspected - although I was out at work at the time.

I'll get up in the loft again this evening with a rake. I'll also take some pictures of the inside wall.

As for going up to examine the gutter myself, I'm crap with heights and accident prone!

This sounds like a potential nightmare!