1930s house - floorboard insulation

[Paulh_Boats]

I've just had a good chat with the local building inspector. By sheer luck he has a very similar house and like Desperate suggested to just insulate under the living room floorboards.

Can I work steadily across the floor one metre at a time, lifting just a few floorboards....instead of removing all floorboards in one go? And which insulation is the easiest to fit?

The carpet is a bit old and I'm wondering if laminate flooring would be a good investment for a rental house, partly for the "wow" factor and I'd hope it would be harder wearing than carpet and not too expensive if I fit it??

Finally do 1930s fire places have their own foundations? If they rest directly on the floorboards it might be impossible to lift the floorboards without wrecking the fireplace. Having said that the fire place does look a bit old.....


cheers
Paul

[dhaslam]

The fireplace should normally be  solid underneath. One thing that might be useful to do  when  the floorboards are  up is to put a closable vent  from under the floor to just in frot of the fireplace.    This helps to stop draughts when using an open fire because the air isn't being taken from the room.     

[desperate]

Hi Paul

No problem doing it bit by bit, I would use 10cm of celotex or similar and tape up the joints with ally tape, we have laminate in our houses and the tenants love it, easy to clean, hard wearing, looks nice, and cheap, about 10 quid a metre at that "Rooster" kitchen shop, give them some old bunny and you can get 60% discount. The fireplace and hearth are almost certainly built off the ground and not on the floorboards.

Desperate

[tony.]

paul,

i fitted 100mm rockwool batts under my floorboards, I cut a hatch at least 600mm( the width of a batt) to gain access below.
batts are cut slightly larger than the gap betwen the joists and squeezed in place.
easy peasy.

tony

[Paulh_Boats]

Thanks for all the replies.  This stuff looks good and Screwfix stock it:

http://www.ybsinsulation.com/pdf/Foil-Tec.pdf


Note: The critical factor is the 50mm to 150mm air gap - the system cuts down radiation across that gap, like double glazing does.


On balance I think lifting all the floorboards is easier than grovelling around in the dirt underneath!


cheers
Paul

[tony.]

paul, it isnt a problem lying on your back putting in insulation, its far less effort than taking up a old floor and relaying it.

the rockwool batts come shrinkwrapped and i can get 3 in my car(golf) at a  time.

i would get it on the market asap, plan for some remedial works between lets,that way you have a income to pay for the insulation/other work/trades.

tony


edit.  the insulation on the link, you dont tape the joints!!!, surely this will allow cold bridging to take place, better off will lo tech rock wool jammed in the gap, no foil tapes required, no membranes required, no taking skirting boards off.

[Paulh_Boats]

paul, it isnt a problem lying on your back putting in insulation, its far less effort than taking up a old floor and relaying it.

the rockwool batts come shrinkwrapped and i can get 3 in my car(golf) at a  time.

i would get it on the market asap, plan for some remedial works between lets,that way you have a income to pay for the insulation/other work/trades.

tony

edit.  the insulation on the link, you dont tape the joints!!!, surely this will allow cold bridging to take place, better off will lo tech rock wool jammed in the gap, no foil tapes required, no membranes required, no taking skirting boards off.

Tony,

Thanks for the advice - I should have got it on the market already, but my Grandmother was the first tenant in 1931 and its been in the family ever since, parents bought it in the 1980s but now deceased. I'm their only son and inherited the house last year...so its been a bit emotional to deal with the house and I've put things off until now.

The no-tape rule for the reflective foil insulation is to allow moisture to drain way, the 100mm overlap must prevent bridging. Each installer claims their system is best    


The house is empty so lifting most of the floor boards is no problem, once the first one is up a crow bar should make it easy. I'm sure the 1930 boards will be thick hardwood and strong enough to take a crow bar - modern T&Q is like match sticks by comparison!

The picture top-right looks do-able, I used the non-itch stuff on my solar cylinder and it does what it says on the tin:
http://www.selfbuilder.net/products/insulation_01.html

cheers
Paul

[Jonathan]

Paul,
I lifted some 1930s floorboards, and as you say they were very strong. However, the tricky bit was not breaking the Tongue and Groove on each board. Without the top bit of the T&G, you're left with tram lines, which eventually show through the carpet!