Damp Concrete Ground Floor
Discussion
Hi
Trying to buy my first house and it has just been surveyed. I had pointed out strange bubbling under the carpet. When we lifted the carpet it had a mdf type boarding which was bubbling. When we broke through that the surveyor checked it with the meter and it was damp. Also the concrete in the kitchen and the same bubbling and damp can be seen and felt in the hall and other room.
This house hasn't been lived in for 2-3 years so possible plumbing may have frozen/leaked but unlikely all through ground floor I would have thought.
Anyway surveyor says it needs a new damp proof course. How much will that cost me in Sevenoaks/Kent area for 3 bed semi?
Might put in UFH while at it (as needs re plumbing).
Will doing the damp proof coursing mean anything else needs redoing?
Can anyone recommend good builders, plumbers, brick layers, carpenters etc. in Sevenoaks area as I will be doing an extension and having to fix the house up.
Thank you
Simon
Trying to buy my first house and it has just been surveyed. I had pointed out strange bubbling under the carpet. When we lifted the carpet it had a mdf type boarding which was bubbling. When we broke through that the surveyor checked it with the meter and it was damp. Also the concrete in the kitchen and the same bubbling and damp can be seen and felt in the hall and other room.
This house hasn't been lived in for 2-3 years so possible plumbing may have frozen/leaked but unlikely all through ground floor I would have thought.
Anyway surveyor says it needs a new damp proof course. How much will that cost me in Sevenoaks/Kent area for 3 bed semi?
Might put in UFH while at it (as needs re plumbing).
Will doing the damp proof coursing mean anything else needs redoing?
Can anyone recommend good builders, plumbers, brick layers, carpenters etc. in Sevenoaks area as I will be doing an extension and having to fix the house up.
Thank you
Simon
I was told recently that I should make sure I wrap my radiator pipes to prevent the concrete from eating into them (I removed a radiator when I took a wall down and had to cap off the pipes below the floor level, so had to dig up the concrete a bit first). If this hasn't been done (or the pipes are just old I suppose) then the pipes could have holed in multiple places. I've often wondered about the lifespan of UFH as the pipes are plastic and I've seen how brittle plastic pipe work can get over time. I wonder how older UFH systems are doing (not sure when this started to become more popular?) as that might give/take away my confidence in going this route myself in the conservatory.
A damp proof course protects the walls against rising damp, and has nothing to do with the floors - I would also be cautious of damp meter readings on concrete as special techniques are used for concrete floors, with "standard" electronic mositure meters designed and calibrated differently and giving completely meaningless results on concrete.
I'm unclear from your description of the floor as to how it is constructed, but on the basis there is a concrete subfloor it could be dampness rising through the floor slab due to the absence of a damp proof membrane. Equally, if the house has been empty for some time, it could be plumbing leaks or condensation. How old is the house? - prior to polythene membranes, many solid floors were laid without a membrane and depended on the adhesive used to adhere the tiles to the surface to prevent the passage of moisture.
If the floor is faulty, it will need to come out, and gives you a great opportunity for insulation and under floor heating.
I'm unclear from your description of the floor as to how it is constructed, but on the basis there is a concrete subfloor it could be dampness rising through the floor slab due to the absence of a damp proof membrane. Equally, if the house has been empty for some time, it could be plumbing leaks or condensation. How old is the house? - prior to polythene membranes, many solid floors were laid without a membrane and depended on the adhesive used to adhere the tiles to the surface to prevent the passage of moisture.
If the floor is faulty, it will need to come out, and gives you a great opportunity for insulation and under floor heating.
The house is an old council house. Probably around 1960 (sorry I'm not much use on that). It appeared to just be concrete. Where we punched through the hardboard "bubbles" the concrete looked like it had corroded - dimpled/small craters and concrete dust. Another bit of carpet I felt actually seemed damp.
What tiles are you talking about? Is that what they put under the concrete or are you talking about tiles on top of the floor as there are none of those (except the kitchen with lino type tiles).
Thank you for your help.
If the floor has to come up any ideas on people to talk to for quotes or ideas on cost. As I will need to renegotiate the price if that is the case.
What tiles are you talking about? Is that what they put under the concrete or are you talking about tiles on top of the floor as there are none of those (except the kitchen with lino type tiles).
Thank you for your help.
If the floor has to come up any ideas on people to talk to for quotes or ideas on cost. As I will need to renegotiate the price if that is the case.
Edited by YarisSi on Tuesday 16th March 19:42
If it's 1960 it probably did not have a membrane installed. The floor probably would have had thermoplastic tiles laid in a bituminous adhesive but sounds like these have been removed. If a floor does not have a DPM any wooden sheet material laid on it is going to deteriorate, so first thing is to take all that up. We've become obsessed with damp proof membranes and vapour barriers but there is a school of thought that says let the floor breathe and you won't have a problem, so good quality, non-foam back, carpets will allow what little moisture passes up through the floor to evaporate away. If you want to lay vinyl floring anywhere there are special underlays available that allow it to be laid on damp concrete.
That all said, when you come to sell, there may be queries raised on membranes, possibly raised by unknowledgable surveyors who do not understand damp meters (I'm a chartered building surveyor and speak from experience before other surveyors take me to task), so if you are planning on doing works to the house then taking the slab out and replacing it is a job your builder should be able to do. Excavate out for at least as much insulation as required by the Building Regulations, if not more. Be prepared to have to take down minor internal walls, for example to stair spandrels, which may be built straight off the slab. If you are installing central heating, then I'd definitely recommend putting in underfloor heating at that time as it is so comfortable and pretty efficient with good insulation; decide early on as it will influence the depth of screed the slab caters for.
That all said, when you come to sell, there may be queries raised on membranes, possibly raised by unknowledgable surveyors who do not understand damp meters (I'm a chartered building surveyor and speak from experience before other surveyors take me to task), so if you are planning on doing works to the house then taking the slab out and replacing it is a job your builder should be able to do. Excavate out for at least as much insulation as required by the Building Regulations, if not more. Be prepared to have to take down minor internal walls, for example to stair spandrels, which may be built straight off the slab. If you are installing central heating, then I'd definitely recommend putting in underfloor heating at that time as it is so comfortable and pretty efficient with good insulation; decide early on as it will influence the depth of screed the slab caters for.
hairyben said:
Could just be cos it's not been lived in and thus heated over the winter? some properties are susceptible this way- a landlord I know had problems with a bunch of polish who didn't heat the house at all, then it was damp after being fine for years.
Don't talk to me about polish tenants! I just had to spend £6000 on a rental house after a bunch of polish people had trashed it completely 
OldSkoolRS said:
I was told recently that I should make sure I wrap my radiator pipes to prevent the concrete from eating into them (I removed a radiator when I took a wall down and had to cap off the pipes below the floor level, so had to dig up the concrete a bit first). If this hasn't been done (or the pipes are just old I suppose) then the pipes could have holed in multiple places. I've often wondered about the lifespan of UFH as the pipes are plastic and I've seen how brittle plastic pipe work can get over time. I wonder how older UFH systems are doing (not sure when this started to become more popular?) as that might give/take away my confidence in going this route myself in the conservatory.
AFAIK concrete will attack copper pipes over time - hence for underfloor heating plastic is the way to go. The most damaging thing for plastic is UV from sunlight, keep this away (ie buried in concrete) and it is supposed to have a minimum life of 50 years. Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff