UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Orb
 
Posts: n/a
Default Damp inside loft wall

I live in the top flat in a converted Victoria house dating from about 1850
which has a lot of damp problems. There is a lot of water damage to the
inside of the gable wall in the loft. The wall is basically brick and
aggregate which is literally crumbling away (in the worst place, about 10cm
depth of brick is missing).

I want to repair the wall. My first thought was to apply some sort of damp
seal to the wall, then some mortar. However, if damp is coming through the
wall, this could make matters worse by trapping moisture. My current
thinking is maybe I should repair using a lime mortar without any damp seal.

From what I can make out, the last time the exterior wall was decorated was
in 2000. Where necessary, render was repaired using cement render and
painted with an oil-based paint. I've used quite a bit of bitumen paint
around the chimney stacks and top of the gable wall. There are no obvious
points where water is penetrating (no windows, no guttering etc.).

Thoughts?

thanks,
Andrew


  #2   Report Post  
David W.E. Roberts
 
Posts: n/a
Default Damp inside loft wall


"Orb" wrote in message
...
I live in the top flat in a converted Victoria house dating from about

1850
which has a lot of damp problems. There is a lot of water damage to the
inside of the gable wall in the loft. The wall is basically brick and
aggregate which is literally crumbling away (in the worst place, about

10cm
depth of brick is missing).

I want to repair the wall. My first thought was to apply some sort of damp
seal to the wall, then some mortar. However, if damp is coming through the
wall, this could make matters worse by trapping moisture. My current
thinking is maybe I should repair using a lime mortar without any damp

seal.

From what I can make out, the last time the exterior wall was decorated

was
in 2000. Where necessary, render was repaired using cement render and
painted with an oil-based paint. I've used quite a bit of bitumen paint
around the chimney stacks and top of the gable wall. There are no obvious
points where water is penetrating (no windows, no guttering etc.).

Thoughts?


A few thoughts (disclaimer of expertise, though).
I am assuming from what you have posted that the gable end includes a
chimney stack .

(1) Oil based paint and bitumen on the exterior wall may not be a good
idea - if the damp cannot escape outwards it can only go inwards. External
paint should be breathable to allow moisture to escape, including moisture
generated inside the property which will have a tendency to rise to the top
with warm air.

(2) If there is a lot of damp, suspect the roof and the chimney pots. Broken
or weathered tiles, especially the place where the tiles meet the top of the
wall, and the mortar on top of the chimney stack around the chimney pots.
Also the flashings where the roof meets the chimney stack. Possibly best to
get a roofing contractor to check it all out - gable ends can be quite
dangerous! If the chimneys are no longer in use, they should be covered with
a cap (e.g. a ridge tile) which allows them to breathe but prevents water
dropping down.

(3) If the chimneys are still in use (e.g. for a gas boiler or open fire)
then are they lined properly or are they leaking? Gas boilers, gas fires and
wood burning stoves all have low flue gas temperatures which leads to
condensation in the flue. All these should have flue liners.

Main point - find the source of the damp and cure it. Trying to trap it in
the wall and hide it generally just causes more problems.

HTH
Dave R


  #3   Report Post  
stuart noble
 
Posts: n/a
Default Damp inside loft wall


Orb wrote in message ...
I live in the top flat in a converted Victoria house dating from about 1850
which has a lot of damp problems. There is a lot of water damage to the
inside of the gable wall in the loft. The wall is basically brick and
aggregate which is literally crumbling away (in the worst place, about 10cm
depth of brick is missing).

I want to repair the wall. My first thought was to apply some sort of damp
seal to the wall, then some mortar. However, if damp is coming through the
wall, this could make matters worse by trapping moisture. My current
thinking is maybe I should repair using a lime mortar without any damp

seal.

From what I can make out, the last time the exterior wall was decorated was
in 2000. Where necessary, render was repaired using cement render and
painted with an oil-based paint. I've used quite a bit of bitumen paint
around the chimney stacks and top of the gable wall. There are no obvious
points where water is penetrating (no windows, no guttering etc.).


This sounds like a problem for the whole building rather than just your
flat. How many flats are there? Do you have a residents' association, or
proper arrangements for maintenance?
In an ideal world the whole wall should probably be hacked off, a membrane
installed, and re-rendered but of course the flats which aren't affected
will be reluctant to pay their share. Same with the roof. Nobody on the
ground floor thinks it's anything to do with them.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Taking out a wall and building regs... Adam UK diy 8 August 21st 03 10:39 PM
(another variation on) soundproofing party wall DP UK diy 0 August 14th 03 09:20 AM
Overflow extended length from external wall - Building Regulations Jeff Martin UK diy 1 August 13th 03 11:37 PM
Wall mounted bath taps Roger Wareham UK diy 1 August 6th 03 03:49 PM
Fitting A Loft Ladder Andrew McKay UK diy 4 July 14th 03 06:10 PM


All times are GMT +1. The time now is 03:31 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"