Treating mouldy floorboards - anyone?!

[Hotpinkparade]

We have water damage to our engineered wood floorboards, and they have developed mould. It’s been going on for months under carpet and we didn’t realise 😭

Pictures attached - any suggestions for what we should do next?! Pics show before and after cleaning with white vinegar as advised by the internet, and we have a dehumidifier arriving tomorrow on a week’s rental to try and dry things out.

They’ll need sanding down I imagine to get them looking good but if under carpet then just let them fully dry and cover again? Are they going to be exposed - as in are you taking the carpet out? For the hassle of hiring a big belt sander and the noise / mess I’d just rip them out and replace as if it’s just that area the cost won’t be huge.

Have they warped from being wet? I agree with pp. I would rip them out and replace.

Yep. Could still be damp underneath.
Is this an insurance job?

They don’t seem to have warped yet but obviously that’s a worry. Not covered by insurance for complicated reasons so really trying to minimise any money spent!!

Not really sure what you mean by engineered wood floorboards.

The whole point of engineered wood I thought was to put a veneer of nice looking wood on top of less nice looking wood. This both makes it cheaper, look nice and less prone to stuff like warping and it is used in visible areas. Not quite sure why you would do that then cover it in carpet.

I think in your case (not a damp expert) the first thing to do is make sure it is all thoroughly dry. What is below the wood flooring and how much moisture may be trapped underneath ? This is what you probably need to think about.

If it is just cosmetic engineered wood flooring over another floor then I would probably take it up to dry it all out and allow what is beneath to dry out, it should be a relatively simple job to then decide whether to keep or replace.

If it is your actual floorboards, I don't know but I am sure someone will have some suggestions. The solution probably depends a lot on where this water has actually been coming from.

What’s the underfloor? Are the floorboards joisted with a void? If so, and they’ve been saturated, it’s likely that the joists will also be damp and possibly whatever’s below.

I think this one of those scenarios where trying to save money now isn’t going to be cost effective in the long run as any moisture trapped below the floorboards is just going to keep on creating damp and later, rot. If you’re not going to replace then ideally you need to lift at least some of them and have an industrial dehumidifier hose under there to dry everything thoroughly.

Rip out and replace. Don't waste time trying to fix this.

Thanks guys. To answer some of the questions - water came from a leak in the bathroom next door and, yes, probably is under the floorboards as well.

The engineered wood is laid on a concrete subfloor.

Having the carpet on top is not our choice, but necessitate by our lease. So however we will have to put carpet back down once everything is dry/fixed. As such I’m not massively bothered about what the floorboards look like, but need them to be dry and not mouldy before replacing the carpet. Hence my massive reluctance to replace lovely (or at least, they were lovely!) floorboards we won’t be able to see!!

Not really quite sure what the point of keeping them is if you can never have them because of the lease.

If it were me I would just take them up and replace with appropriate underlay and carpet.

I guess you might get a few quid for them if you sell them presuming they are not damaged for refit and can be sanded.

If I don’t replace the floorboards then the floor in the hallway will be lower than the rest of the flat! So there will be a step up in to each room, which I’d prefer to avoid.

Totally different story but we are also appealing against the decision that we have to have carpets - it’s a long game but ideally we’d like to have the floorboards there in case we’re ever successful.

I mean if you want to keep them in there fine. I would just bear in mind that it might be difficult to put them back in once you take them up if they have swollen up with the water. And if you choose not to take them up you are probably going to have to dehumidify for a long time to suck the water out of them and the water trapped between them and the floor beneath. There is also a question I guess as to whether they have been glued down in which case they will be hard to get up.

Good luck !

I’d then definitely rip out and start again. Won’t be a big or expensive DIY job and you can get some cheap and cheerful boards as you won’t be seeing them anyway. If the damage was caused by next doors bathroom then you can ask them for the money? Or do you mean your bathroom next door? Either way, pull them up and replace in my view.

So they are not true floorboards, but a floor, if I understand your post correctly?

If I were you, in the circs I wouldn’t waste money trying to salvage them. I’d take them up, let everything dry, put down underlay and carpet. You’ll spend money and create mess trying to fix them. You may be able to put OSB or something underneath to level the floor. (I’m not a flooring expert) but I’d be tempted to live with the mismatched levels until you know the outcome of the lease negotiations.