hi, im moving into a old house. approximately 1950s. in the past week we've noticed around the edges of concrete floor, in the kitchen lounge and hallway. That the previous flooring had been pushed up by what appears to be a white limescale looking substance. the floor isnt overly wet possibly slightly damp if anything. theres cracks in it too some surface cracks and some deep cracks. its mainly the perimeter walls but there is slight build up on a middle section next to the middle wall. we have dont really know what is causing it. we dont think its a leak of a pipe as the areas of concern are too wide spread. we dont think its roots of any trees as they are not that close to the house or large enough. any ideas or knowledge of this? ng12 area.
Sounds very much like a failed Damp proof membrane or even possibly Red Ash. http://houseconveyancing.org/problems-caused-by-red-ash/
If it's a 50s house, I'm doubting it even has a DBM, the white limescale looking stuff could be concrete/cement salt seeping up through the joint between the slab and brickwork due to the underside of the slab being damp/wet.
i dont have a picture at the moment. could that lack of DPM cause the cracking? what would be a fix to this issue? how do i check if it has a DPM? also would it the problem be located always around the edges. though i havnt taken up the whole carpet this is where it seems to be located. i noticed it due to raised carpets. when i pulled them back i noticed that the carpet had been laid onto tiles. (not ceramic) it goes tiles>underlay>carpet. the white substance was pushing up the tiles which in turn raised the carpet. it seemed to be where the tiles met. guessing the is where they were weakest. i have also noticed this white substance where there is no flooring. under kitchen units for example. where i first dismissed it as limescale from units. sorry for babbling, just trying to offer as much evidence as i can think of.
trying to look up things online, would it be possible for a bridged damped proof course to cause this. as seen here http://www.dryfix.net/blog/bridged-or-failed-damp-proof-course/ another thing i read was that, the damp proof course can also divert water to under the main concrete slab causing symptoms of rising damp.
Speak to neighbours see if anyone else has had similar problems, maybe council to see if there is a problem with that area/development. The tiles sound like Marley ones are they brown and brittle? If so fair chance they contain asbestos, not a high risk in normal use, but you should be aware if you are having the floor ripped up or repairs done.
As said some piccies would help, Dark brown / black might well be Marley (thermoplastic) tiles usually about 2mm thick, common in properties from 50's to 70's particularly ex local authority and flats.
As others have said it would appear to be "Floor Heave" The symptoms you quote " the floor isnt overly wet possibly slightly damp if anything. there's cracks in it too some surface cracks and some deep cracks. its mainly the perimeter walls but there is slight build up on a middle section next to the middle wall." are exactly the same as I had in my property in Birmingham approx 1998, it became an insurance job but it has to be proved that a leaking pipe has allowed water to get to the floor fill material which in my case was Power Station type ash which then causes a reaction between the concrete and the ash which swells and pushes up the concrete. The solution with mine and numerous neighbours was to move out while the builders removed the entire ground floor infill until soil was reached and then refilled will inert material and the floors made good, out of property for approx 4 weeks all the load bearing walls were built on foundations and not a floor slab so no structural problems The house was built approx early 40s Hope this helps
This is what ive found under the worst part of the floor. Im guessing you guys have an idea what it is. To me its like cured clay. I was told 3 houses up the road from me. There was a water leak while it was unoccupied that went on for several months. Going straight under my house and out the side on the neighbours driveway. So many possible factors. When pulling this material out the floor did feel damp. But not overly damp. also ive gone 16inch down so far and still havnt reached solid ground. its still this rubbish.
im told this might be the thing they use to used to put under the concrete. looks like pit waste to me which is very possible as thats what this house was built for and by.
haha no. ive only got around to investigating it today. ive been doing the garden and upstairs first. i was dreading dealing with this one.
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