Acceptance of the wonderful damp

[kev208]

We have now accepted and come to love our damp so I need as many solutions for minimising the problem as you wonderful people can come up with.

We have a Victorian terrace with a modern(ish) concrete floor downstairs in the hall and back room, the front room has a suspended timber floor. we have what looks like rising damp intermitently around the whole ground floor. after posting on various websites like this one, having perplexed 'professionals' round to look at it and doing my own research I have concluded (!) that the concrete floor is pushing moisture to the edges of the room and up the walls. we may also have a failing damp course but I dont want to get into this as we cant afford to re-inject/replaster etc (I'm not convinced it is failing either).

so, we are going to decorate the whole ground floor and need to know the best ways of going about minimising the problem. so far I have come up with following potential ideas:

-take off skirting boards, attach wooden batten under the level of the plaster but above the concrete floor to absord moisture, put skirting back on.

-ventilate skirting baords at various points

-damp proof concrete floor with sealant(?) before carpeting ??

-use damp proof paint as an undercoat (does this stuff work in these circumstances or at all?)

we are intending to paint the front room (timber floor) but the back room and hall need papered as the walls are in bad shape. should we be taking a different approach for the intended papered and painted rooms?

any comments on the above welcome as well as any other ideas...

[Phil L]

This is a newsgroup, not a website, but carry on..

You've concluded wrong Kev, and more to the point, you are wasting any money and time you throw at this unless it's spent on installing a DPC.

It is, or I should say, it already has...what you think a DPC involves when you say you 'can't afford it' is beyond me, would you say the same if your roof blew off?

Complete waste of time, effort and money - if you are taking any skirting boards off, you should drill two holes in each brick and inject them with DP liquid or gel - bollocks to the firms who install and 'gaurantee' it - do it yourself, both to save money and for your own comfort.

No, DP paint is crap, it's cosmetic, like everything that you have mentioned so far, none of it will stop the water rising through the brickwork until you install a DPC

If you want to keep spending money on decorations every year, put up with damp walls and risk timbers rotting (and inviting dry rot to destroy the rest of the timber in your house) carry on...but you are throwing good money after bad...how many 'professionals' have you paid to come and look at it so far? how much time and money have you spent on it so far? How much do you think it costs to hire a sds drill and purchase a few drums of DP liquid and a pump? - all that hacking off 1 metre of plaster is tripe (I know because we used to install DPC on every house we renovated from 1981 to 1995) - it's only to satisfy the chemicasl company and to provide the installers with extra money, for your own house, just remove skirtings, drill, pump and replace skirtings, 3 months later no damp - redecorate and forget.

[kev208]

clearly I like the sound of this, what sort of price are we talking?

I must admit though all of the above ideas are the accumualted knowledge I have got mainly from posting on here - the common theme being "damp proof course isn't failing, concrete floor the cause, sort the problem and don't waste money on more injecting etc..."

I think I'd be convinced by your argument if there werent the random patches of damp - can the DPC fail in intermittenly in various different areas.

also the main area of damp is in an internal partition wall, would this have even had a DPC?

[Phil L]

Yes, I had damp in a wall that was about a foot long and a foot high, nothing on each side of it and the wall was 12ft long!

the victorian method of DPC was often slate, this was sometimes laid on a thin bitumen coating, sometimes the slate wasn't used at all and just bitumen was applied at DPC level, sometimes nothing at all....I have seen houses with no semblance of a DPC whatsoever and they have been totally dry, others have had slate, bitumen or a combination of both and been ringing wet - it all depends on the ground underneath the house...areas where there is a lot of sand in the soil will rarely suffer from rising damp because it doesn't hold in the ground too long, other areas where the ground holds a lot of moisture all year round will sufer damp problems, so there is no wrong or right way concerning DPC's. If there was no DPC there at all, it still doesn't mean that the wall would be evenly damp, some parts of the foundations may have better drainage than others and some bricks are softer and more porous than others...also if there is a dpc and it's failed, it may hve only failed in places, not all over, bitumen cracks up in winter and runs in summer when it gets very hot.

All downstairs walls, interior and exterior have (or should have) a DPC in them.

The cost of hiring a dampcourse pump is about £30 for a day, a SDS drill and a 10mm bit will cost about the same, unless you know someone who would lend you one, the liquid is about £25ish (25L) and a mid terraced will take about

2.5 drums...there is a gel which someone mentioned in her a while ago which doesn't require a pump...

If you decide to do it, take off all the skirting boards downstairs, drill the whole thing out, keeping the same course all the way through and then go and hire the pump, unless you can get someone to drill for you, in which case you can start pumping immediately. The corresponding course of bricks outside will need doing also, front and back, plus an upstand of about 30 inches where it meets next doors or a garden wall etc.

One man can do one house easily within a day, two men can probably do three!

[kev208]

Thanks. The house had a DPC in 1992, the installer has since gone out of business. the main walls affected are internal or on the party wall with the neighbour. doing the outisde may also be tricky because the wall contrcution is stone dressed brick.

presumably the new dpc would need to go abpve the concret e floor but below the suspended timber floor? also, is it best to avoid the bricks that have already been injected?

[Phil L]

Cladding? - this should not have bridged the DPC when it was applied, if it has you may need to double drill from inside.

Is the concrete floor the same level as the wooden floor? - if it is then keep the same course all the way around, if you can get underneath the wooden floor easily enough and there is suitable access, then do underneath the wooden floor, but where the concrete floor starts, you will need to step it up so that it joins onto the course you will be drilling above the concrete, like this:

Wood V :............... ..............:concrete ^

[.]

I did a house similar to what yours sounds like. the dining room floor was old 'concrete' with quarry tiles over it. the 'concrete' had failed and the quarry tiles were semi mobile. it was possible to lift a few of them off by hand and the house was listed as being damp. it had a new concrete slab poured over a DPM and sealed with bitumen. all walls were silicone injected and the bottom yard of plaster was hacked off, as was/is the fashion. that cured the damp but, with the CH installed, warped most of the nice old victorian doors.

ya live and learn.

[EricP]

Having had exactly that configuration in such a house, I think you will find that the room with the concrete floor was intended as a scullery, and that room and hall, had bricks laid directly on the bare earth. The suspended floor is where the servants were supposed to exist, hence the luxury of a dry floor.

Unless one has lived in such a house, the damp from the floor is unimaginable.

[The Natural Philosopher]

I have to agree.

I lived with this sort of damp for year..and the only thing that works is putting the heating on and opening the window.

That or stopping it getting in.

Under a house should not BE that damp...it doesn't get rained on...often the bigger problem is that water isn't being cleared from around the house, or worse, with suspended floors, is actually running underneath.

A french drain often helps a lot, and with suspended floors a sump with a pump and a float valve.

Injection DIES work as long as the brickwork isn't so inaccessible or so wide that you can't do it properly.

[The Natural Philosopher]

You have been listening to people who have read something on period homes, haven't understood it, and think they know everything.

Yes. if injected.

Thats the issue. On my house I had the same, and the primary reason was they injected from outside, and made a DPC that way - the original had none - but they simply didn't DO the internal walls

In my case the problem was worst where the floors were wood. The main reason for that was water was collecting under the suspended floors. Where they had laid concrete on a DPC it didn't even get under the house at all.

An internal wall is a good candidate for injection, but you have to go low and deep. Or skirtings will rot.

[The Natural Philosopher]

"sometimes you just can't win"

[Mark]

Eeek I know of several houses in Eastbourne that had this done 20+ years ago a complete disaster You have 3 options Renew the DPC again as Phil's advice, on party walls I would use

avoid the possibility of filling the neighbours house with chemicals / smells its also much more DIYable.

fit tanking

from floor to _above_ ceiling level and arrange ventilation from skirting level to exterior via ceiling void to outside wall.

Dig up the concrete and do the complete job properly.

-

[Stuart Noble]

Not much help I know, but every house I've been in where a suspended floor has been replaced by concrete has suffered damp. I don't see how it could be "pushing" the moisture to the edges, but it does leave damp only one route if it's coming from below. I've known French ditches make a big difference but they have to be fairly deep I think dpc injection is probably your best move. Relatively cheap and easy if you d-i-y, and then at least you can eliminate that source.

[kev208]

Update for what it's worth. Taken off some skirting at the point where the damp is most evident ie at the junction on the internal partition wall bentween the suspended timber floor front room and the concrete floor hall / back room. there is a blue plastic membrane sticking out

3-4 inches from under the concrete floor which may give its age away (?). there has defineitly been a DPC as I can see the holes. the bricks are dry but the plaster above is sodden.

took a look under the floor boards in the front room. cant see back twoards the area mentioned above as there is an original stone supporting wall under the floor boards blocking my view. whatever is going on, the worst of it would seem to be coming from this area.

also looked round outside of house and existing DPC in external walls appears to be about an inch above the house floor level

[kev208]

also... the chemical compnay in 1992 when the DPC was installed was Palace Chemcials who are still in business (and not liable of course!!).

here is a photo of the main offending wall with skirting removed. timber floor front room to left of shot, concrete floor to foreground and right of shot

[meow2222]

1. Wrong approach.
2. Wrong newsgroup. UK-d.i.y has a great range of expertise, but it falls short when it comes to damp in period properties. Try here:

[Stuart Noble]

Picture won't load.....

[kev208]

Try this

[Stuart Noble]

That's better. So this is an internal wall and you say the bricks are dry, but the plaster above them is wet? It could be that the bricks dry out and the plaster, being more absorbent, is retaining water. See if the bricks are wet after heavy rainfall. One is tempted to say you have rising damp, possibly because of a high water table, and that it's soaking up into the walls. Presumably the concrete floor was put in to address the problem and it's driven it to the sides i.e. your original diagnosis :-). Then again, concrete is colder than wood and, depending on the aspect of the house, heating conditions etc, may be causing condensation. In that case the floor itself would be damp under the carpet, and it would be unlikely to affect the room with the suspended floor. Give periodproperty.com a go and let us know what they say. However, as with all these damp problems, you can't beat observation and commonsense.

[kev208]

Observation and common sense led me to my original conclusions which have been roundly deconstructed above. periodproperty has been tried and they were of no use unfortunately other than to suggest taking the concrete floor up which I would like to do but it's a job a bit beyond my means. i think reinjecting is the answer. in the meantime we have tracked down the builder who did the original dpc in 92. he is retired but is happy to come and have a look....