Help - Rotten Floord Boards and Joists

maybe_tomorrow_2

I have just lifted up old carpet, and underlay wooden panels to expose the floor boards in the living room. Upon doing so I have discovered that in two corners of the room the floor boards have settled slightly causing a gap of around 25mm between floor board and skirting board along one side of room. Also appear to be rotten locally in corners off room.

In one area I took up one of the floor boards to find moisture on the joist surface, is this normal?

Is it likely the joists are rotten causing the slight settlement? elsewhere in the room is fine, i.e. floor boards flush with skirting, and floor boards seem sound, the problem is just along one side of the room. Slightly worried now, would appreciate any advice.

Should I get a carpenter out or just a good builder to inspect?

Regards

Gloomendoom

No, it's not normal. It sounds like that there is inadequate ventilation under the floor. Have you checked that the airbricks/vents are unobstructed?

phill99

Gloomendoom wrote: »

No, it's not normal. It sounds like that there is inadequate ventilation under the floor. Have you checked that the airbricks/vents are unobstructed?

No. It does not sound like there is inadequate ventilation.

The floor has dropped for some reason and there are many reasons to consider. Moisture in the wall plates is a distinct possibility and ONE of the causes of that is inadequate ventilation.

Please do not jump to conclusions and give poor advice.

[Deleted User]

I've just bought a house with similar issues.

You would need to identify and eliminate the source of moisture before renewing/repairing joists.

For my house, it was due to the roof and gutters not doing their jobs for several years prior to purchase.

If I was you, I would try and identify how moisture is getting there.

Do you know what's under the floor boards?

maybe_tomorrow_2

Thanks. There is quite a big void under the floor boards and foundations. No insulation or damp proofing under boards, should there be?

The joist had beads of water on the surface like condensation or dew. I should note the heating has not been on in a long time until yesterday. I wonder would this have any impact on showing water droplets on joists, this wouldnt apply to rotten/sunking boards/joists though.

What would be the best trade to come and inspect?

Thanks

phill99

Just get a general builder to inspect.

[Deleted User]

maybe_tomorrow wrote: »

Thanks. There is quite a big void under the floor boards and foundations. No insulation or damp proofing under boards, should there be?

The joist had beads of water on the surface like condensation or dew. I should note the heating has not been on in a long time until yesterday. I wonder would this have any impact on showing water droplets on joists, this wouldnt apply to rotten/sunking boards/joists though.

What would be the best trade to come and inspect?

Thanks

I'm guessing your house is quite old then? Do you know how old?

Under the floor boards in my house is just a void until you get to the earth/soil. I don't think it's a problem unless there's evidence of rising damp (which is rare). The solution to that would be visqueen and a layer of concrete.

Penetrating damp is more common which means water is getting in from the roof or gutters overflowing, or something like that.

Are your rotten joists on an external wall? Is there any pipe work near the area in question, or any other potential source of moisture?

The best trade to look at it would be a damp proofing company. The big national ones are Peter Cox / Rentokill / Timberwise. They will usually come and have a look for free but I wouldn't take what they say as definitive.

maybe_tomorrow_2

1902 or thereabouts. Yea it looks like a void then earth/soil. The rotten floor boards are localised in 2 corners, the joist that had the "dew" was a random loose floorboard that I lifted up, the joist seemed sound to my judgement but was just surprised to see water.

It is the fact that it has settled which worries me.

[Deleted User]

maybe_tomorrow wrote: »

1902 or thereabouts. Yea it looks like a void then earth/soil. The rotten floor boards are localised in 2 corners, the joist that had the "dew" was a random loose floorboard that I lifted up, the joist seemed sound to my judgement but was just surprised to see water.

It is the fact that it has settled which worries me.

What prompted you to lift the carpet and floor boards?

maybe_tomorrow_2

We were planning on putting down new laminate floor so needed to remove old carpet, we then noticed that there was nice floorboards which we could potentially clean up and use as flooring instead, 95% room was dry, level and definitely re-useable as natural floor, as was the hallway. But now seeing the void underneath I am inclined to stick with placing new flooring over the top.
It was only when we came to the floor boards against front of room where windows are that there appeared to be some settlement of boards. it is only a small area of floorboard which appears damp/rotten in comparison to the rest of the room. A new DPC was installed a few months back throughout groundfloor.

tony6403

Don't be too alarmed but a 25mm gap is not "slight" movement and is highly unlikely to be settlement.
Not easy to identify the exact cause from your post but I would have a close look at the area where the floor joists are supported against the wall.
Often in older properties, these are simply slotted into the walls and the ends may have rotted and failed.
As Phill says , could be a wallplate problem (but I don't think that you will have a wallplate).