Damp proofing floors

[Piff]

Brother in law & wife have just moved house to a 1960's chalet bungalow.
They have found some damp issues & I have investigated.
The concrete ground floor does not have a damp proof membrane and it seems that damp proofing was provided by the use of vinyl tiles stuck down with a bitumen based adhesive.
All fine until previous owner removed the tiles & most of the adhesive in the lounge before fitting underlay & carpet.
In the kitchen there are areas (probably under the original kitchen fittings) where there have never been any tiles/adhesive)
In a ground floor bedroom the tiles are still there but are broken/lifting around the edges where carpet grippers have been nailed.

A couple of coats of synthaprufe is an option but possibly not directly under a carpet.
In the kitchen they had intended to have vinyl flooring.

Any ideas on a damp proofing product which could be painted over the concrete/old butumen and would not affect carpets or vinyl laid over it?

 

[verytalldave]

I doubt whether a durable product that you require exists. Not one where a carpet can be laid directly on top of anyway.

Look here for tips............... Damp-proofing solutions for solid concrete floors from Safeguard Europe Ltd.

 

[Dieselman]

Dig the floors out and relay with a DPC. It will be much better in the long run.

A thick coat of bitumen may suffice, but isn't really the answer.

How did that get past building regs?

 

[Piff]

Dig the floors out and relay with a DPC. It will be much better in the long run.

Cost is an issue.

A thick coat of bitumen may suffice, but isn't really the answer.

How did that get past building regs?

1960's
I have seen it before in council houses of that age.
My current house (also 1960's) has a 20mm asphalt screed.

 

[Dieselman]

Cost is an issue.



1960's
I have seen it before in council houses of that age.
My current house (also 1960's) has a 20mm asphalt screed.

My house has an asphalt screed, but the concrete oversite is still damp proofed.


If cost really is a problem, just paint the concrete with hardener if it's unstable then a few coats of bitumastic paint should seal it.

 

[renault12ts]

My house has an asphalt screed, but the concrete oversite is still damp proofed.

Which is good...but an exception.

 

[Piff]

If cost really is a problem, just paint the concrete with hardener if it's unstable then a few coats of bitumastic paint should seal it.

They have moved to the house with (they hope) sufficient funds to re-fit kitchen & bathroom
Damp has come as a surprise therefore no budget.

Unfortunately they have a damp meter and percieved problem is being blown out of proportion.

They have had "advice" from a window salesman yesterday (part of the kitchen re-fit), advising them to remove conctrete paving slabs from around the building & replace with shingle - this will cure the damp
The slabs are laid 6" below dpc and are no problem at all.

The main problem I found is that the internal bath waste pipe (ground floor) is not actually connected to the external pipework where it passes through the external wall. The pipe touches the external fitting so when the plug is pulled on the bath, 50% of the water goes down the drain & 50% goes into the cavity, washing round the cavity, soaking the brickwork below dpc level and transferring to the concrete floor/screed as there is no seperating membrane.

Bath waste cured for less than £5. However, with their damp meter they are checking everything & worrying themselves silly.

 

[Dieselman]

Does the place smell of damp?

Now the waste is fixed most of the problem will go away, but just Bitcho the B.

 

[Piff]

Does the place smell of damp?

Now the waste is fixed most of the problem will go away, but just Bitcho the B.

Big stink under bath when panel removed (had been siliconed all the way round)
Didn't particularly notice smell round rest of house.

 

[Dieselman]

Didn't particularly notice smell round rest of house.

Not damp then, is it.

Has SIL tried the damp meter on her head/chest/arm/piece of dry paper...etc.

Anything that conducts any electricity will register on a damp meter.

As a test for the concrete being damp they could tape a polyethylene sheet down to the concrete, leave for 24 hrs then lift and look for condensation on the sheet and sweating on the concrete.

were the old carpets damp on removal?

 

[balge]

Too right, instant 'spot the cowboy' when a 'damp meter' appears... had a damp problem at mine when I was renting, Council muppets insisted it was 'rising damp' and had a DPC done....and another a year later when the damp was even worse (done really badly too ).

Eventually forced them to fix the real problem - the cellar was full of rubble breaching the original damp course (slate iirc?), all the ventilation in the cellar was bricked up or blocked, and damaged gutters and downpipes sluicing water down the walls...but the 'damp meter' proved it was 'rising damp'

It's entirely possible the bath was the whole problem, if there is still an issue, could you put a suspended floor in? Proper ventilation is the enemy of damp
cheers

 

[LTD]

Takes ages to get rid of any leak that is a result of a water leak.

I had a cistern leak a few months ago and it's almost dried out now.

A dehumidifier can certainly speed things up but be aware of un-neccessary shrinkage issues if you dry out too quick - you might end up in the world of redecoration.

 

[Piff]

Takes ages to get rid of any leak that is a result of a water leak.

I had a cistern leak a few months ago and it's almost dried out now.

A dehumidifier can certainly speed things up but be aware of un-neccessary shrinkage issues if you dry out too quick - you might end up in the world of redecoration.

Dehumidifier going into the room they think is the worst (bedroom next to bathroom)

Needs total redecoration anyway.

 

[Piff]

Not damp then, is it.

Has SIL tried the damp meter on her head/chest/arm/piece of dry paper...etc.

Anything that conducts any electricity will register on a damp meter.

As a test for the concrete being damp they could tape a polyethylene sheet down to the concrete, leave for 24 hrs then lift and look for condensation on the sheet and sweating on the concrete.

were the old carpets damp on removal?

Would love to try it on SIL's chest

I have punched a hole in the kitchen floor next to external wall. About 5" depth of concrete/screed then damp clay. No evidence of polythene under concrete or synthaprufe between concrete & screed.

Bedroom still has vinyl tiles on bitumen adhesive, but tiles are breaking around edges as gripper strips removed. Lounge carpet on underlay with tiles/bitumen underneath having been removed by previous owner. Floor registers damp on their meter. Kitchen has cheap laminate over most of floor. I was able to knock hole where dishwasher removed as there was no laminate there.

I could tape down a sheet of polythene but I'm sure that would show condensation after 24 hrs.

This issue has (had) them so stressed that after moving in on Monday they are convinced they have bought a money pit and by Tuesday/Wednesday they were talking of needing to re-sell & move house.

 

[Piff]

It's entirely possible the bath was the whole problem, if there is still an issue, could you put a suspended floor in? Proper ventilation is the enemy of damp
cheers

Cost is an issue.

If I can find a paint on product - such as the one in the link from verytalldave - I think that will put their minds at rest.

Have asked SIL to advise what floor finishes they expect to end up with in bedroom/lounge/kitchen. I will then contact Safeguard Europe for advice.

 

[davidjpowell]

How long has the house been empty? While it's not as bad as winter, any house is going to show additional dampness if it's not been lived in and air has not been circulated.

Confiscate the damp meter! I noted that someone suggested putting your hand over the prongs - its exactly what I do when I'm not convinced that my meter is working -it spends too much time in my briefcase...

I would not think it would be majorly expensive to sort. There is this stuff,Restoration UK | LVM Damp Proofing Paint 5L | Damp proofing | tanking and timber treatments | waterproofing buildings | managing condensation | woodworm | dry rot but they would have to add a thin screed afterwards.

 

[davidjpowell]

oops. duplicate..

 

[Piff]

How long has the house been empty? While it's not as bad as winter, any house is going to show additional dampness if it's not been lived in and air has not been circulated.

Confiscate the damp meter! I noted that someone suggested putting your hand over the prongs - its exactly what I do when I'm not convinced that my meter is working -it spends too much time in my briefcase...

I would not think it would be majorly expensive to sort. There is this stuff,Restoration UK | LVM Damp Proofing Paint 5L | Damp proofing | tanking and timber treatments | waterproofing buildings | managing condensation | woodworm | dry rot but they would have to add a thin screed afterwards.

House not previously empty.
Recently divorced lady, 2 children & guinnea pigs did a house swap with them with cash adjustment - she needed to downsize for divorce settlement.
I have said to them they should not have a damp meter and if they throw it away they would not have half the problems.
In some ways it is a good job they noticed something - not good to have bath waste pipe not connected!
I'll have a look at Restoration UK.

 

[finisterre]

if I was them I would start digging. A few inches of kingspan under a new floor will pay for itself in reduced bills within ten years. Better value tha a new kitchen.

 

[Benzowner]

Many years ago, we tanked out a basement that had damp coming through the walls and floor and used a product called Bituthene. Its a polythene membrane with a bitumen coating. The main problem you may have with puting a damp membrane onot the floor, is that it will or may be higher than the wall damp proof coarse.