Insulating floors in victorian house

[versioncity]

After a bit of advice or comments on what I'm thinking of doing:

Recently bought a large victorian terrace that hasn't been touched for a good few years. There's a sizeable draught coming up through the ground level floors. The house has a double cellar & a crawl space at the back end underneath the kitchen.

the plaster on the cellar ceiling is the original horsehair plaster & has a few gaping holes & non-existent in places. I was thinking of ripping all the original ceiling plaster off to expose the joists. Then getting rockwool, filling in between the joists with this & then nailing up chipboard or some sort of membrane to keep it all in place.

does this seem like an ok idea? Any issues? - My only thought is that this would stop any ventilation between the joists, is this ok to do.
Also I'm pretty skint so whatever I do it needs to be on the frugal side.

 

[PrenticeBoyofDerry]

The question I would first ask would be "are there any electrical cable in this ceiling/floor void?" as the current carrying capacity can be reduced by the addition of thermal insulation.
The second question "any damp issues in the cellar?" as I would steer away from the use of chip board and use plasterboards with vapour check barrier.
Third question"can you identify were the draft is coming from?" as this would be my first point of investigation for elimination!

 

[versioncity]

Thanks for replying-

yes there are some cables between the joists, but these can be re-routed relatively easily as they are all "loose" - cheers I didn't know that.

yes there is a little damp in the cellar, nothing too bad, but it does attract some mildew(?) and white fungus type growths over a period of time.

The draught can't really be eliminated in the cellar, it comes through the airbricks & there is just a general cold down there which comes up in winter. The cellar has stone slabs on the floor which I presume are just laid on top of the earth so there is no way of stopping it apart from having the cellar tanked, but I can't afford to do anything like that at this point.

If not using woodchip, is there anything you would recommend? - I guess some sort of plastic?

 

[foxhole]

The air movement is ventilation for the floor boards, to prevent them rotting.

 

[versioncity]

so what to do then?

 

[foxhole]

Ensure the rest of the property is draught proofed , around window and doors and especially loft acees to reduce overall air movement, but do not stop it or you invite mold and condensation.

 

[Harbourwoodwork]

QUOTE OP yes there is a little damp in the cellar, nothing too bad, but it does attract some mildew(?) and white fungus type growths over a period of time

your first job is get that fungus sorted the moisture content is too high that fungus will romp through a damp old victorian house it will travel right up to the roof if you leave it Iv'e seen it

 

[versioncity]

thanks for the advice, but can anyone advise on my original question about stopping the draught/cold coming up from the cellar through the floorboards.

 

[foxhole]

Lay carpet.

 

[JohnD]

the cellar is cold, and needs to be well ventilated to keep it fairly dry. Verify that you have plenty of airbricks and other ventilators that are not blocked with rubble or cobwebs.

Packing loft quilt (which is subsidised and very cheap) between the joists of the floor above will block the draughts and also provide insulation. It sounds like you will have to pull the old plaster off.

Thick old plaster has the advantage of forming a fire barrier. Yours is probably lime on laths and will be thick and heavy, which also blocks sound. I would probably nail up two layers of plasterboard to restore the fire barrier above the cellar, but I am very cautious.. Stagger the joints. You have not got to skim it unless the room is going to be decorated or you are obliged for some reason to make it officially fire-resistant.

Remove any rubbish, especially scraps of wood, from the crawl space as it is liable to harbour rot and woodworm.

 

[versioncity]

John, thanks.

there are airbricks in both cellar rooms & one down the far end under the kitchen crawl space. I keep them clean of dirt.

yes the plaster is old/lime/horsehair type stuff. & I was planning on packing between the joists as you mentioned, but other posters seem to think this will cause rot to the floorboards above(?) - then nailing up some sort of cheap ceiling material to keep everything in place & hopefully cut down on the draught. - I don't quite understand why it would cause rot because of lack of ventilation as originally there was an intact cellar ceiling in place which would have prevented ventilation anyhow & the floorboards are fine.

Why do you say you would be cautious?

 

[JohnD]

that's why I would prefer to reinstate plasterboard as a fire barrier to protect the ground floor.