Saturated concrete floor with mould after long term drain leak

TWP1995

Hi All,

I moved into my house last Feb and discovered a leaking drain in the side of the house (kitchen sink drain hopper in ground next to outside wall of house resulting in sink water sitting against concrete slab of kitchen/subfloor of hall). This had clearly been going on for a long long time. I had the drain repaired a while back.
Knowing that the concrete slab below the kitchen lino was saturated as a result, I thought I'd remove the lino to aid drying out of the slab with a dehumidifier etc. over the next few months. However, under the lino there is extensive black mould and cracking of the slab.

My questions are therefore twofold:
1. How should I go about removing the mould growth, bleach, water and elbow grease (with masks etc)?
2. What's the best way of speeding up the drying of the concrete slab?
(3. what else should I consider/think about...?)

Many thanks in advance...

[Deleted User]

Buy or borrow a dehumidifier to start with, that will help dry it out. Get proper masks too, mould can be nasty stuff.

Fire_Fox

Welcome to MSE.

Wear disposable masks with a filter, disposable gloves, use a dedicated mould and mildew killer. Follow the product instructions which usually advise treat, allow time to take effect, rinse, leave to dry.

Limit movement in the area, including scrubbing, because this encourages mould spores to become airborne. Lift affected flooring slowly and gently for the same reason.

Consider the quality of the filter in any dehumidifier and replace it regularly. Ideally wear mask and gloves when changing the filter or cleaning the unit since dry mould may still pose a health risk.

bouicca21

Is it not covered by your buildings insurance as consequential damage? If si they will send a drying company to inspect and recommend what action to take.

cyclonebri1

Treat the mould whilst it's still damp, it's pretty safe at that stage.

The slab could take a year to dry out provided the ONLY problem has been fixed and also the floor is left uncovered. More otherwise.

Don't rule out condensation caused by a little damp and a non permeable (lino) membrane stopping it clearing.

Given the issue the slab sounds uninsulated which only adds to any issues, may or my not even have a dpc under/in the concrete dependant on age.

If there is a long term issue you may need to consider more serious remedial work, suck it and see for now.

shaun_from_Africa

Fire_Fox wrote: »

Limit movement in the area,

Especially any pets. Dogs and cats will lick their paws to clean them and if they have been walking over the mould, I'm sure it wouldn't do them any good.

bouicca21 wrote: »

Is it not covered by your buildings insurance as consequential damage? If si they will send a drying company to inspect and recommend what action to take.

From the OP's description it sounds as if the leak may well already have been there when they moved into the property and if this is the case then their insurance wouldn't cover it as it would class as a pre-existing fault.