Filling void under suspended floor

[Lamentable]

Just wondering if it's possible to fill in the void under my suspended floors?

- two reception rooms approx 16m2 each.
- the void is around 4ft deep
- various electrical cables need to be considered that go to sockets throughout the room

The objectives are to improve thermal performance, install underfloor heating in both rooms and stop the somewhat annoying ingress of slugs into the rooms from the void below.

I've read the floor can be filled, then have rigid insulation board put in followed by the heating circuit and screed on the top. There is a damp course to add as well.

Please let me know if this is possible, or if it's a bad idea.

Thanks in advance.

 

[robinbanks]

That's a lot of fill. Perhaps re-floor lower in block n beam, insulate and screed over to come up to present level?

 

[Lamentable]

I'm not familiar with block and beam as such. What do the beams sit on?

 

[robinbanks]

The walls, usually, after you've bashed holes in them

 

[noseall]

Just wondering if it's possible to fill in the void under my suspended floors?

1.2m is a lot of fill as said, and will likely settle. B&B will be too difficult, especially considering that you need 100mm bearing on both leaves. This would mean access to the outside walls at a certain depth and lots of holes in the outside walls - or build new internal walls off new foundations - again too much aggro.

 

[Lamentable]

Out of interest, what is the settling time?

 

[noseall]

Out of interest, what is the settling time?

It could be instant, depending on how you lay and compact the material.

 

[blup]

Just wondering if it's possible to fill in the void under my suspended floors?

- two reception rooms approx 16m2 each.
- the void is around 4ft deep
- various electrical cables need to be considered that go to sockets throughout the room

The objectives are to improve thermal performance, install underfloor heating in both rooms and stop the somewhat annoying ingress of slugs into the rooms from the void below.

I've read the floor can be filled, then have rigid insulation board put in followed by the heating circuit and screed on the top. There is a damp course to add as well.

Please let me know if this is possible, or if it's a bad idea.

Thanks in advance.

Insulation is important, so is ventilation assuming you have air bricks. Just fix insulation under floor boards, batten the joists to the required depth to secure in place, but leave room for air to flow.

Blup

 

[JohnD]

Slugs, eh?

If you fill it in you will lose all ventilation.

What do you think is the cause of the damp?

Where is ground level in relation to the dpc?

How many air bricks do you have?

Do you have old drain gullies?

Heat loss through a floor is very slight. You can insulate if you want. Your damp problem is more pressing.

 

[JohnD]

if it's a bad idea.

Yes.

 

[Lamentable]

Isn't the ventilation needed because of the wooden joists so if they no longer existed it wouldn't be required?

(I'm not a builder)

I'm not sure there is any damp. I think the slugs just "wonder" in through the air bricks then find there way up through the floor boards.

 

[JohnD]

I'm not sure there is any damp.

The slugs say there is.

 

[Lamentable]

I have noticed drops of moisture on the skirting boards in the same area the slugs were spotted.
I was at a loss as to how they appeared there as the carpet isn't wet so I wasn't sure how the spots had formed.
The floor boards under the carpet are also dry to the touch.

 

[JohnD]

Might be condensation from a leak under the floor. Plumbing commonly starts leaking anytime between one minute and 50 years after fitting.

You didn't answer about the DPC and drains.

 

[JohnD]

BTW it is a source of annoyance when an old wooden floor has been replaced by concrete, to find that the reason was rot caused by a leak, that was never repaired, and has led to chronic damp and a bill a hundred times greater to dig up the concrete to get at it.