Victorian Basement Flat internal walls badly spalled

[malc_p]

The thread title doesn't do this justice, by far!
We've lived here for 25 years, the flat is a basement of an 1860's victorian terrace and was converted back in the 1980's. It was obviously whitewashed bare brick before so the "developer" battened and plasterboarded every internal wall. The floors are screeded and we don't know what is beneath, probably brick and no damp course.
Anyway; we've had the bottom of the walls in the living room blowing the plasterboard so we've decided to rip it out and have a look.
The cause of the blowing is spalled brick dust and it's several inches deep. The battens are, surprisingly, in pretty good condition although some have rotted at the bottom. The lower plasterboard panels have been painted with black bitumen (I think).
Main issue is, many of the lower bricks - up to about 5 or 6 courses - are badly spalled (but there's also a kind of furry coating in one place that as far as I can see isn't fungal but crystalline). See pics for what I mean.
Anyhow - what's the best way to proceed? I'm going to clear up the loose dust and brush down the brickwork and probably replace the battens, but do I use a masonry sealer or should I get the bricks replaced somehow (I think the wall in the pics is a supporting wall)? Should I go ahead with wood or galvanised steel battening?
The stuff on the back of the black-coated panels in the pic is spider web not fungal.
The nuclear option of "cover it up and move" is not feasible unfortunately!
Cheers
Malc

 

[blup]

The thread title doesn't do this justice, by far!
We've lived here for 25 years, the flat is a basement of an 1860's victorian terrace and was converted back in the 1980's. It was obviously whitewashed bare brick before so the "developer" battened and plasterboarded every internal wall. The floors are screeded and we don't know what is beneath, probably brick and no damp course.
Anyway; we've had the bottom of the walls in the living room blowing the plasterboard so we've decided to rip it out and have a look.
The cause of the blowing is spalled brick dust and it's several inches deep.

Replace tne bricks and put in a dpc, ideally physical but an injected one is probably better than nothing. You also have an opportunity to add a dpm

The battens are, surprisingly, in pretty good condition although some have rotted at the bottom.

Treated wood should be fine, use plastic plugs and spacers to keep wood from touching the brick. Maybe add suitable insulation

The lower plasterboard panels have been painted with black bitumen (I think).

Replace damaged pb

The nuclear option of "cover it up and move" is not feasible unfortunately!

Cover it up and stay.

 

[Ivor Windybottom]

There's no purpose for a DPC, it's underground.

It's a botched basement conversion. It needs major repairs, overhaul and proper damp-proofing.

It's probably not suitable for habitation.

Do you measure the humidity? You should be aiming for 60% in the UK to be healthy. Do you get black mould in cold places?

Honestly I wish the answer was just to cover back up, but I doubt that's a good answer.

 

[malc_p]

There's no purpose for a DPC, it's underground.

It's a botched basement conversion. It needs major repairs, overhaul and proper damp-proofing.

Time to get a surveyor in, I think. We own 1/6 share of the freehold and as it's pretty clearly structural we should be able to get the cost shared. I'll instruct our managing agent accordingly.
Re "major repairs" I'm totally at a loss as to how this should be approached!

It's probably not suitable for habitation.

Would a surveyor condemn it as such and could we be forced to move out if the local council were made aware?

Do you measure the humidity? You should be aiming for 60% in the UK to be healthy. Do you get black mould in cold places?

Haven't got a hygrometer but we have a dehumidifier that runs at about 80%. No black mould but anything leather gets a white fur in summer.

Honestly I wish the answer was just to cover back up, but I doubt that's a good answer.

It's tempting. The previous job lasted 40 years, that's more than long enough to see the both of us out and into a care home!
<JOKE!>

 

[noseall]

Replace the bricks and put in a dpc,

What happens when the walls start pushing in?

Treated wood should be fine, use plastic plugs and spacers to keep wood from touching the brick.

I would not put timber anywhere near those floor/walls.

 

[blup]

What happens when the walls start pushing in?

The OP didn't describe bowing walls, just damp. They have been there in conversion for 40 odd years and originally built in the 1860's. I was suggesting replacing the spalled bricks to resolve the damp. Would you add wall straps?

I would not put timber anywhere near those floor/walls.

Metal?

 

[malc_p]

The OP didn't describe bowing walls, just damp.

Yup, that's about right. All the walls are true and it's just in a couple of corners where there's obvious damp. Both these corners are on the wall adjoining next door, but the original building next door was comprehensively remodelled in 1943 by Messrs. Hitler & Heinkel, and the resulting bloody great hole infilled in 1966 and a nasty contemporary block of flats built there. Their ground level is about 2 metres above our floor level so what the infill consisted of is anybody's guess and how thick the wall is between us and that is similarly uncertain. But this is where we're getting damp from, and I can't see any way it is going to be fixed barring knocking down the eyesore next door (which is another tempting prospect).
So we're stuck with mitigation remedies.

They have been there in conversion for 40 odd years and originally built in the 1860's. I was suggesting replacing the spalled bricks to resolve the damp. Would you add wall straps?

Metal?

We rebuilt our back bathroom and replaced all battening with metal stud, I don't like that you can't just hang a shelf or a towel rail on the batten with a couple of #8 screws like with wood, but have to use specialist fixings and so on. But if that's the way to go, then we'll do it.

 

[blup]

the original building next door was comprehensively remodelled in 1943 by Messrs. Hitler & Heinkel, and the resulting bloody great hole infilled in 1966 and a nasty contemporary block of flats built there.

One of the joys of walking through East London ( I don't know where you are) is occasionally seeing old Victorian buildings that neither Herr H nor the post war planners managed to destroy.

 

[tony1851]

With that basement to do a proper job you really need to consider tanking up the walls and across the floor, with a pumped drainage system. That is the only way to do a permanent job on it without any future problems.
The white furry stuff is salts, a sure sign of dampness.

 

[blup]

Agreed but Unless the OP can squeeze a contribution from the other freeholders he might be better off to do a more basic decorative job keep tne damp at bay for a few years and gtfo.

 

[mrrusty]

As @tony1851 says, the white fluffy stuff is salts. They are hygroscopic and will be growing from damp both coming from the brick and from the humidity in the air. I'm not going to comment on what you should do with a basement as I have no personal experience of ever doing this. The only thing I can add is that I have stabilised very badly spalling and crumbling outside lavvy walls by wirebrushing back and then using an SBR slurry of almost neat SBR and cement, which once painted with masonry paint has proved to be surprisingly durable.

 

[Ivor Windybottom]

What most people do with a basement is nothing. They weren't normally intended for living in. Sometimes for servants and cooking/laundry perhaps.

If you're going to live in one then essentially you need to create a completely isolated new building within it. Together with a drainage system to take away the water that finds its way into the gap between the two. This will cost lots and make the internal space within much smaller.

Some interesting history there. So essentially what was a party wall became a retaining wall for infill. Probably rubble, which will be essentially porous to water. The new building's rainwater drainage probably connects with this, so you may well have become their soakaway.

80% humidity isn't habitable.

Honestly, you should question your attachment to the place. Cover-up and go would be my choice.

I don't know how shared freehold works in this situation. I'd suggest getting independent private legal advice before opening the can of worms. If your basement flat needs a massive amount of damp-proofing then some or even all of it may be chargeable to all occupants, 1/6th each. I don't know how this works, but you could argue that it's the same logic that would also force you to pay 1/6th of the cost of roof repairs, even though you don't adjoin it.

 

[cdbe]

That's an internal wall (there's a radiator pipe coming through it), so it will be rising damp and can be remedied with a suitable dpc (there was probably never one there as it was originally a basement) looks like they just asphalted the floors and lined the walls instead of continuing across the entire floor.

If the right hand wall is the external wall it appears to be the worst area and needs stripping to investigate - if this is similarly damp it will need vertical tanking and a vertical dpc where it abuts the internal wall.

I would have thought in a leasehold flat that would be considered a structural issue and the costs shared.

 

[Ivor Windybottom]

You really think all that damp's coming up from the floor? Impossible. The pipes are an interesting mystery though.

It was an internal wall. Now it isn't, there's a load of infilled stuff behind it and the sky above it.

 

[cdbe]

I think (but obviously don't know), that the wall facing us is an internal wall with another room on the other side, in which case it would benefit from a dpc that would be continuous with the floor dpm. If the right hand wall is the party wall now backfilled with whatever from the new construction next door there's no point installing a dpc - needs fully tanking as said.