Really confusing damp patch on brick.

This Forum is for all questions relating to Rising damp, Penetrating Damp, Basement Drainage, Cracked Masonry and Wall tie replacement.

Moderator: Moderators

Post Reply
evoman
Newly registered Member
Posts: 5
Joined: Tue Jun 16, 2020 8:19 pm
Has thanked: 0
Been thanked: 0

Really confusing damp patch on brick.

Post by evoman »

Hi,

Been trying to trace this issue for about a year. I’ve got a damp patch that appears about head height in my garage when it rains. The garage is completely brick, it has a new pitched fibreglass flat roof above. I thought the new roof might resolve this issue but unfortunately not.

The wall backs onto my kitchen, it’s a wall with no pipework other than gas & electric. The water runs on the other wall both downstairs & upstairs, no radiators or anything on this side where the damp patch is appearing. It’s also only when it rains just to clear it being a leak up.

The roof above is fine as this issue was before & after the new roof, I’ve had kitchen roll above the damp patch to see if it is running down and no, just this one patch which is really confusing me.

My only possible thought is that there seems to be way more weep holes above the flat roof than I’d ever expect, I can see the damp course below the row of weep holes, but could it possibly be relating to this? Although it still confuses me how it’s travelling so far down & only ever effecting these few bricks. Also to note, there’s no damp showing on the inside of the kitchen, not to the paint at least.

The leak is to the left towards the pitch but still just above the flat roof.

I’ve also had the lead on the pitch redone aswell as repointed where the mortar was cracked.

Photos are in next post - I’d really appreciate any help as I’m lost, doing both parts of the roof hasn’t helped & I’m really lost at this point! My next step was to investigate the weep holes, whether to partially block some of it to stop some rain water going in - there seem to be way more weep holes & I’ll be honest I’ve never seen them placed above a flat roof before.

Thanks everyone!
Last edited by evoman on Tue Jun 16, 2020 8:41 pm, edited 2 times in total.
evoman
Newly registered Member
Posts: 5
Joined: Tue Jun 16, 2020 8:19 pm
Has thanked: 0
Been thanked: 0

Really confusing damp patch on brick.

Post by evoman »

Image
31D67086-D543-4DC4-9FD3-D898D0C5B369.jpeg
31D67086-D543-4DC4-9FD3-D898D0C5B369.jpeg (733.52 KiB) Viewed 203 times
Attachments
90091E67-C210-4293-B291-257D8910E5C0.jpeg
90091E67-C210-4293-B291-257D8910E5C0.jpeg (294.94 KiB) Viewed 203 times
User avatar
big-all
Pro Carpenter
Posts: 21745
Joined: Sat Dec 16, 2006 10:11 pm
Location: redhill surrey an auld reekie laddie
Has thanked: 650 times
Been thanked: 1978 times

Really confusing damp patch on brick.

Post by big-all »

can be anywhere up stream then run down a surface hit a tie or bit off wood then deflect
is there a window or other structure above
we are all ------------------still learning
evoman
Newly registered Member
Posts: 5
Joined: Tue Jun 16, 2020 8:19 pm
Has thanked: 0
Been thanked: 0

Really confusing damp patch on brick.

Post by evoman »

big-all wrote:
Tue Jun 16, 2020 8:54 pm
can be anywhere up stream then run down a surface hit a tie or bit off wood then deflect
is there a window or other structure above
cheers for the reply, nope - no windows above or anything. I can’t see anything above that would cause it. The only thing I’m seeing is the mass of weep holes above the flat roof. And below that is the damp course..
User avatar
ayjay
Senior Member
Posts: 9153
Joined: Wed Nov 17, 2010 5:51 pm
Has thanked: 444 times
Been thanked: 1563 times

Really confusing damp patch on brick.

Post by ayjay »

evoman wrote:
Tue Jun 16, 2020 8:36 pm

I’ve also had the lead on the pitch redone aswell as repointed where the mortar was cracked.
Is that actually lead, or is it Flashband?
One day it will all be firewood.
evoman
Newly registered Member
Posts: 5
Joined: Tue Jun 16, 2020 8:19 pm
Has thanked: 0
Been thanked: 0

Really confusing damp patch on brick.

Post by evoman »

ayjay wrote:
Tue Jun 16, 2020 9:02 pm
evoman wrote:
Tue Jun 16, 2020 8:36 pm

I’ve also had the lead on the pitch redone aswell as repointed where the mortar was cracked.
Is that actually lead, or is it Flashband?
Yeah, there is lead and bostik flashband over it as a precaution. The photo is a few months old, I always forget to take a photo when I’m up there as it’s been repointed now & the lead driven back into the wall.
The lead was original, the lead also went along the flat roof & they kept the original leads in when they fibreglassed - I even called them back to fibreglass trim instead of the lead along incase that was the cause hence the slightly different colour between the 2 fibreglass trims.

I can’t see that it’s water running down the wall, the ceiling in the garage is plasterboard and no marks at all, & I’ve tried taping kitchen roll above the leak to see if that gets wet, not a drop but always the damp below it.
User avatar
big-all
Pro Carpenter
Posts: 21745
Joined: Sat Dec 16, 2006 10:11 pm
Location: redhill surrey an auld reekie laddie
Has thanked: 650 times
Been thanked: 1978 times

Really confusing damp patch on brick.

Post by big-all »

as i say the leek can be anywhere up stream feed into the cavity then out to the wall
as its a suspected heavy rain issue it could be water getting into the cavity from the roof
we are all ------------------still learning
wes56
Senior Member
Posts: 928
Joined: Fri Nov 01, 2013 9:36 am
Has thanked: 3 times
Been thanked: 153 times

Really confusing damp patch on brick.

Post by wes56 »

Just a guess but
It could be that wind blown rain is penetrating the exposed outer wall skin and running down to the cavity trays (what your calling a DPC) where most of the moisture should go out through the weep holes. But there's no signs of the water trickles staining below the weeps?
If the cavity trays are not detailed correctly then some water can get into the cavity below where it is sometimes caught on cav ties or any CWI.
Your flat roof flashing is one course too low, It should go into the same bed as the cav tray.

But usually the damp would show on both garage and kitchen wall surfaces in wider areas?
Some of the detailing on the tiled roof is not too clever but it would probably show up on the ceiling below?
evoman
Newly registered Member
Posts: 5
Joined: Tue Jun 16, 2020 8:19 pm
Has thanked: 0
Been thanked: 0

Really confusing damp patch on brick.

Post by evoman »

wes56 wrote:
Fri Jun 19, 2020 5:47 pm
Just a guess but
It could be that wind blown rain is penetrating the exposed outer wall skin and running down to the cavity trays (what your calling a DPC) where most of the moisture should go out through the weep holes. But there's no signs of the water trickles staining below the weeps?
If the cavity trays are not detailed correctly then some water can get into the cavity below where it is sometimes caught on cav ties or any CWI.
Your flat roof flashing is one course too low, It should go into the same bed as the cav tray.

But usually the damp would show on both garage and kitchen wall surfaces in wider areas?
Some of the detailing on the tiled roof is not too clever but it would probably show up on the ceiling below?
Hi Wes, thanks for the reply I appreciate it.

That’s the only thing I can think of now really. I’d been chasing a few leaks through the previous felt roof, had the fibreglass roof done & resolved all of the leaks once they came back & did the trim to the brick wall as they left it as lead but had some trickles down. They’ve actually followed where the previous lead was into the mortar, so guess it’s always been a level down - I didn’t realise this was wrong. And no, no staining below the weep holes.

What would you advise next? My plans were to put some weep hole covers (not block it off completely, those plastic inserts to stop rain driving in). What would you change on the tiled roof, the leak is that end of the roof but more above the flat but obviously could be running from either side as it’s close to both. Or would you seal the outer wall skin?

I’m hoping to sort it before winter, I’m out there every time it rains currently scratching my head!

Thanks again!
Post Reply

Return to “Damp Proofing and Remedial problems”