Another damp question

[oldbutnotdead]

Morning all,

My 'detached' project house (1850, solid brick walls) has one end wall about 100mm from next doors' end wall- thus external access is limited/nonexistent. Peering into the gap from above shows it has got a fair bit of rubble in it (mostly mortar by the look of it with a few bits of brick), there's no easy way to get the rubble out (gap narrows at the front to about 30mm, gap at the rear is inaccessible due to both our kitchen extensions).

The ground floor internals of this wall are very wet.

What's my best longterm solution to the wet? Can I just clad the walls with something like this http://newtonmembranes1-px.rtrk.co.uk/system-damp-proofing/ or render them with something like this http://newtonmembranes1-px.rtrk.co.uk/cementitious-products/newton-105-cw105/ or should I be biting the bullet, cut some holes in the walls and drag the cack out. Oh yes, and there are chunky chimney breasts on this wall, also very wet.

Thanks

 

[dishman]

Firstly, I would try your best to get some of the rubble out, if there really is a lot. How big is the rubble? Can you not think of a "heath robinson" way of trying to access it. A rake with an extension, holding the rake vertically....slide it down and pull it back towards you?

Secondly, can you give more information on where this damp is situated....

Is is seasonal? Is it on the old solid wall construction or the newer kitchen extension (which I presume is a cavity wall)? Do the areas of damp correspond with the location of the rubble...

Also read this post on damp, and my second post down..and answer those questions?

//www.diynot.com/forums/building/low-level-damp-patches-on-internal-walls.389770/

I would always start by eliminating the simpler things that could cause the damp, things which you can control, before looking at expensive solutions to the problem....

 

[conny]

Is there a way for you to make some sort of long narrow rake and try to pull the 'cack' out via the wide end? Maybe something you could attach to the end of a set of drain/chimney rods?

I would think trying to create a hole in the wall from the inside could be very dangerous to poke your head through unless it was properly supported with all manner of chocks & braces.

 

[dishman]

I see the "heath robinson" rake idea is gaining support!

 

[conny]

Hadn't noticed your post as I was typing mine at the same time.

Oh I am a great fan of Heath Robinson train of thought! Pulled me out of a pickle many a time!

 

[oldbutnotdead]

Firstly, I would try your best to get some of the rubble out, if there really is a lot. How big is the rubble? Can you not think of a "heath robinson" way of trying to access it. A rake with an extension, holding the rake vertically....slide it down and pull it back towards you?

Secondly, can you give more information on where this damp is situated....

Is is seasonal? Is it on the old solid wall construction or the newer kitchen extension (which I presume is a cavity wall)? Do the areas of damp correspond with the location of the rubble...

Also read this post on damp, and my second post down..and answer those questions?

//www.diynot.com/forums/building/low-level-damp-patches-on-internal-walls.389770/

I would always start by eliminating the simpler things that could cause the damp, things which you can control, before looking at expensive solutions to the problem....

Ta for reply. The rubble thing is a bit tricky. This house is fairly old and the gable end wall isn't exactly parallel in any plane with next door. The gap at the top (as in at roof height) is about 100mm, it narrows as you get anywhere near ground level- to about 30mm at the front. The rubble starts about 2000 from ground level. Come sunnier weather I might have a go with a long stick but it'll be a very very dull job.

The kitchen extension was put on in around 1900 I think (there was lead gas pipe for cooker supply but not for lighting- the rest of the house has gas pipe for light in it). That's solid walls as well- I think the back wall is only half brick (there are no soldier course in it) so I'm reluctant to start drilling a million holes in it for injection DPC. The plaster (sorry the 2 inches of bonding coat and the plaster skim) was all very wet when I hacked it off, the tiles had fallen off.

The major damp is in the breakfast room- have a couple of pics.

Chimney breast

• oldbutnotdead
• 19 Jan 2014
• 2

Check out the damp line

LH alcove

• oldbutnotdead
• 19 Jan 2014
• 1

Walls are sopping wet, underside of floorboards were wet, joists have started rotting (but...

Plan with notes

• oldbutnotdead
• 19 Jan 2014
• 1

The floorboards from the alcoves beside the chimney breast were actually wet on the underside when I lifted them- that may be due to the poor ventilation (only about 50mm under the joists, even less that that in the front room which is the only air source for the back of this room). The walls in the alcoves are wet up to about 1500, you may be able to see where I marked the damp tidemark on the chimney breast.

In terms of the damp questions- the place is a building site rather than a home at the moment so they don't really work. I don't remember the damp being that obvious on the chimney in the summer but there was a cement mixer parked against it so I might not have noticed it.

I am going to try a fire in the fireplace and see if that improves matters (I rebuilt the top of the flue last year so it is airtight). [

 

[dishman]

Hmm, you have so much going on, that you are correct, it will be hard to diagnose or see if you get any improvement with it being a building site at the moment...

...has the house been empty for long? Are you heating the house/that room at the moment?

Getting the fireplace working should definitely help dry that wall/chimney breast out.

You say there was damp under the floorboards.....if there is that much you may also want to consider a dehumidifier whilst you do the works....dry it out as much as possible...

I still think that (while being a very long boring job) clearing out that gap will be worth it. If there is lots of rubble in there and it is wider at the top than the bottom, there must a decent amount of rainfall which will fall down there just absorbed by the rubble, which I assume is up against the wall. I doubt it will dry out very quickly either as it won't be getting much sun. Obviously I am basing this on your description...

 

[oldbutnotdead]

Hmm, you have so much going on, that you are correct, it will be hard to diagnose or see if you get any improvement with it being a building site at the moment...

...has the house been empty for long? Are you heating the house/that room at the moment?

Getting the fireplace working should definitely help dry that wall/chimney breast out.

You say there was damp under the floorboards.....if there is that much you may also want to consider a dehumidifier whilst you do the works....dry it out as much as possible...

I still think that (while being a very long boring job) clearing out that gap will be worth it. If there is lots of rubble in there and it is wider at the top than the bottom, there must a decent amount of rainfall which will fall down there just absorbed by the rubble, which I assume is up against the wall. I doubt it will dry out very quickly either as it won't be getting much sun. Obviously I am basing this on your description...

Aye, place has been empty for about 10 years, there's no central heating- downstairs fireplaces were in use, upstairs had a convector heater on the landing. Poor old dear.......

I'll have a go at a fire in that fireplace. One thing that doesn't show in the pics- I found 2 bits of copper pipe coming out of the right hand side of the chimney breast into the alcove. They'd been roughly hacked off, no idea when- quite likely when most of the rest of the metal in the house went missing (not that there was much) but that would indicate to me that there's been a back boiler in that fireplace.

Actually looking at the grate there is a rusty metal thing at the back with a gap under it (no pic accessible at the mo) so I suppose that could be the boiler.

Will it go BANG if I light a fire with no water in the thing?- I have zero experience of solid fuel water heaters. I suppose one interesting experiment would be to dig out the tube ends (plaster should be deep enough for me to get a couple of pushfits on the ends), link them to a water vessel and see what happens.

Dehumidifier- is there any point given that I can't seal the room very effectively? (That is a serious question. I have got a dehumidifier, just didn't see the fun in trying to extract water from the world).

I've covered the gap at the top of the house as well as I could- 2 bits of gutter running between mine & next doors wall and draining onto my roof. The gutters are Flashbanded to next doors' wall and to my wall where the drip edge from my parapet wall isn't. (Next door has a single apex pitched roof, mine is twin apex). I probably need to develop something cunning to see whether the covering is working- hmm, have to think about that.

And yes you're right about the cack in the gap- think I'll save that one for when the sun is shining again. Anyone know how much suck you get from a monster vacuum cleaner- I'm thinking a variant on Gold Divers (just been watching it)- long stick to stir the crap up, vacuum tube to lift it out of void. Any big bits will have to be the worlds longest litter picking tongs. Definitely a job for the summer.....

 

[conny]

Now I see why you used the word 'project' in your earlier post!
(Though I think 'job for life' would have been more apt! )

Regarding the c rap again. A long steel bar with the end bent over about 2" may help. By dropping the bent end into the c rap it may be possible to rake it out. As you say though, a long tedious job to do, unless of course you have a Scout troop in your area, Lol

The 'cracks' in the fireplace, did you do that or where they like that when you bought the place? I'm worrying about subsidence to be honest.

 

[dishman]

There are so many factors involved with the house being empty for so long, not being heated, solid walls etc. there could be a number of causes for the damp...

Regarding the dehumidifier, it will still work with ventilation, open windows etc but, if the room is not being heated consistently, there is little point as you need the damp to be able to evaporate to get the best out of a dehumidifier. A dehumidifier with a condenser operates best at around 20degrees I think....

As connie said, I did not realise the scope of your project. It is a bit outside my advice pay grade really!!!

With the house being empty for so long, it probably needs a decent amount of time to dry out......so you may not see the damp situation improve until you get it to a stage where you can heat the whole house consistently. Then get a some good ventilation and a dehumidifier on the case...

Regarding getting the fireplace working, you are maybe best getting someone to inspect it in person.....

Good luck with everything though.....

 

[oldbutnotdead]

Now I see why you used the word 'project' in your earlier post!
(Though I think 'job for life' would have been more apt! )

Regarding the c rap again. A long steel bar with the end bent over about 2" may help. By dropping the bent end into the c rap it may be possible to rake it out. As you say though, a long tedious job to do, unless of course you have a Scout troop in your area, Lol

The 'cracks' in the fireplace, did you do that or where they like that when you bought the place? I'm worrying about subsidence to be honest.

That would be an evil trick to play on the scouts- I remember getting stitched up on Bob a Job week! Not sure I could risk assess a troop of them on the roof or even at ground level with a 5 metre rod and hook. Like your thinking though, come the summer I'll have a look at the drop involved and have a wee play. Might even try the one way flap attachment on my drain rods.

And the cracked fireplace- yes it worried me as well. Structural survey said yes evidence of movement since the place was built but nothing significant for many years, soil is stable, it'll be fine. Tree bloke reckons the 2 massive conifers outside the front door are helping keep the soil drained so advised keeping them but managing them down in size a bit.

Happy days.....