Fix needed for Draughts from suspended floor

[Anonymous]

I own an 1850 house with suspended Timber floors on teh ground floor. There is a 2' void under the floor and one(only) vent to the front of the house. The house appears to have a primitive DPC made of Hair and Tar in the external walls, but no DPC in the internal walls. My floor-boards are butted and are varnished. My problem is that I have draughts from gaps in the floor-boards. I am investigating a number of solutions. 1. Seal the gaps using thin wood wedges or caulking - and possibly adding additional vents to retain or improve the circulation. 2. Place insulation in the void. 3. Install under-floor heating to provide warm air draughts. 4. heat the air coming into the void under the floor. I am also draught-sealing the Sash windows. Any help appreciated. Colum.

 

[Anonymous]

There are various views on underfloor heating, particularly to older houses with timber floors. I understand it is not as efficient in such situations, but others may be able to provide advice based on actual experience. If you have an existing heating system and there is nothing wrong with it, I doubt that it would be cost effective to install underfloor heating.

Whatever you decide to do you must maintain good ventilation to the void to reduce the risk of rot, etc. on no account reduce the ventilation and if necessary improve it.

Sealing gaps will reduce direct draughts from the floor void (and any damp musy smells from the oversite if it gets damp). Draught-proofing windows is always a good thing to do regarding reduction of heat loss.

Insulating the floor will not reduce heat loss significantly (remember heat rises). However, it could improve the surface temperature of the floor and therefore improve comfort levels. If you install insulation it might be best to use a semi-rigid insulation board between the joists, held in place by battens. This can be installed from underneath if you have access. Again, others who have undertaken such work may have more detailed advice.

If you intend laying fitted carpets with underlay, I suspect this could be as effective (and cheaper) than installing insulation under the floor. You could then lay hardboard over the floor surface (under the underlay and carpet) to deal with draughts between boards.

 

[Anonymous]

Just looking into the same problem myself Colum, 'wet' underfloor heating is a lot more expensive to install than a standard radiator setup due in part to the complex brass fittings and control system required, though there is no doubt that underfloor heating per se is the Rolls Royce of heating methods - no cold floors, no radiators to paint or hide AND reduced heating bills. Electric "dry" underfloor heating is much cheaper to buy and install but for myself electric in a non starter even though I'm an electrician, I want my heating from one source only, the gas boiler.
Any heating elements whether wet or dry MUST be insulated to obtain the benefits of reduced bills, this means as well completely avoiding draft corridors. Well fitted insulation between and underneath the joists and around the perimeter of the floor will achieve this, thus avoiding the necessity to caulk floorboards, however, somehow you must gain access under the floor to do this.
I shall remove all my floorboards, renew the DPC, rewire, fit the wet heating pipe, and fit insulation all in one go, the floorboards will then be refitted better than before, a time consuming exercise and costly if not doing it yourself but from my point of view a job well worth doing.
My considered advice is to avoid the hit and miss job of caulking floorboards, bite the bullet and remove them, pin polystyrene sheeting or similar to stop draft corridors and refit the boards. Should you find any damp problems caused by inadequate ventilation bricks this can easily be tackled at the same time. Be aware that house surveyors see hardboard over floorboards as a bodge.

 

[Anonymous]

We had a similar problem with draughts through gaps in the suspended floor boards. I can tell you that a good underlay and fitted carpet solves the problem totally!