Any known gotchas when using 100mm PIR rigid foam between (deeper) attic
floor joists?
I plan to top up with 100mm Rockwool roll and not use the space for
storage of any sort.
Is it required to seal any gaps with tape?
--
Tim Lamb

On 11/06/17 12:28, Tim Lamb wrote:
Any known gotchas when using 100mm PIR rigid foam between (deeper) attic
floor joists?
I plan to top up with 100mm Rockwool roll and not use the space for
storage of any sort.
Is it required to seal any gaps with tape?

Its very advisable

If going in from above use caulk or expanding foam.

Half the point of taping is moisture barrier. I guess that's not going
to happen tho in this case...



--
Renewable energy: Expensive solutions that don't work to a problem that
doesn't exist instituted by self legalising protection rackets that
don't protect, masquerading as public servants who don't serve the public.

In message , The Natural Philosopher
writes
On 11/06/17 12:28, Tim Lamb wrote:
Any known gotchas when using 100mm PIR rigid foam between (deeper)
attic floor joists?
I plan to top up with 100mm Rockwool roll and not use the space for
storage of any sort.
Is it required to seal any gaps with tape?

Its very advisable

If going in from above use caulk or expanding foam.

Half the point of taping is moisture barrier. I guess that's not going
to happen tho in this case...

I stapled up a moisture barrier before fitting the plasterboard. Gaps
will be narrow as I will use the band saw and the joists appear to be
parallel.

My experience of using a foam gun is that I am not very good at
controlling the quantity of foam:-(

Biggest concern is *will BC want it done*.




--
Tim Lamb

On 11/06/2017 20:38, Tim Lamb wrote:
In message , The Natural Philosopher
writes
On 11/06/17 12:28, Tim Lamb wrote:
Any known gotchas when using 100mm PIR rigid foam between (deeper)
attic floor joists?
I plan to top up with 100mm Rockwool roll and not use the space for
storage of any sort.
Is it required to seal any gaps with tape?

Its very advisable

If going in from above use caulk or expanding foam.

Half the point of taping is moisture barrier. I guess that's not going
to happen tho in this case...

I stapled up a moisture barrier before fitting the plasterboard. Gaps
will be narrow as I will use the band saw and the joists appear to be
parallel.

My experience of using a foam gun is that I am not very good at
controlling the quantity of foam:-(


I'd recommend getting an applicator gun - they dispense as much or as
little as you need and the foam stays usable for months. Just be sure to
close the valve after use and give it a good squirt through with cleaner
when you change gun grade cannisters.

I could never get the hang of the disposable sort.

--
Cheers, Rob