Using an expanding foam gun upside down/limited space?

[Lusi83]

Going to insulate under my suspended floor with kingspan boards (I have dithered for ages ...I know expensive etc but limited crawlspace so rockwool would be really nasty to do and thickness to give a decent uvalue would make any future underfloor work unpleasant too -and I can't easily take floor boards up cos they are nailed together on tongue & groove)

Ideally want to seal the gaps with expanding foam gun - but think lack of space will be a problem...just wondering if anyone has any tips /tricks for doing this...

(My gun came with bending tubes but they have a habit of flying off and also not sure I will have enough space even for that..longer tubes? .or maybe a 'slow' foaming one??? -then foaming sides before pushing them between joists? )
If all else fails I plan on stuffing mineral wool into any gaps ...but foam would be better...

Any suggestions?

 

[dhutch]

You can get expanding foam cans that will work upside down.

I also read a threads elsewhere which linked to a artical suggesting the use of spun plastic (from recycaled bottles) 'eco' wool inslulation, which was substatially nicer to work with in limited spaces.

Otherwise, theres always taking up the floor!


Daniel

 

[freddiemercurystwin]

Expanding foam access aside you should be using something to hold the boards up either a few nails or battens rather than the foam or friction.

 

[foxhole]

Very little heat loss thru a suspended floor, seems a pointless exercise.

 

[freddiemercurystwin]

Yes of course it is, its another conspiracy dealt out by the manufacturers and government to make us spend more money.

 

[Lusi83]

Thanks
I had forgotten about eco wool - would be nicer to handle ... but looking at the k rating and the depths supplied I would have a lesser but similar problem - it would have to hang down under the joists a bit (or be compressed) to get a decent U value - so it would reduce the crawl space even more and (from experience) you keep getting caught on the netting...

Why insulate under the floor? I have done in it current house in the living room (with a much bigger crawl space and rockwool) but not in the dining room...and I am convinced there is a difference...The way I look at it a suspended floor is no different from the walls of a shed - especially if you have good underfloor ventilation ...you wouldn't stick a bit of carpet on the walls and expect a shed to be warm...makes perfect sense to me...
(and after freezing in this house I would do anything to keep me warmer in the next one!)

 

[Lusi83]

And I meant to say my plan is compression (and preferably foam) fit then when in place either fix thin batons across the joists every so often or use nails (Board I've ordered is a tiny bit deeper than joist depth - should project fractionally below joists...batons should give a snug fit - but I won't really know until I do it... a learning experience....