Insulating a Roof Gap

[awemawson]

My workshop is a converted barn with corrugated fibre cement sheeting roof. It's been sprayed with expanding foam and when they did it they assured me that they'd sealed the apex where there is a 'top hat' shape.

Well they obviously didn't - I recently had an enormous bonfire ( 1/2 mile of Leydandii hedge top  ) - and there is a line of 'fall out' ash down the length of the workshop. So if the ash blew in then my heat MUST be able to go out 

No chance of getting them back, as access is now very difficult with all the machines in place, and I don't want them covered in foam anyway !

SO - my thought was some form of insulating sausage that I can poke up there with a long stick - if there was such a thing as a 6" diameter cylindrical shape I reckon it would stay in place by friction.


  BUT YOU MAY HAVE OTHER SUGGESTIONS PERHAPS 

[vtsteam]

What about pipe insulation? Or the colorful equivalent "pool noodles" ?

[awemawson]

That was my first thought Steve but I've not found any in the UK of a sufficient diameter - above 35 mm bore it all seems to go into foil wrapped fibreglass which won't have the 'friction staying' power I think

[bertie_bassett]

How about 3or more of the pool noodles duct taped together?? Wont be the best looking, but might do the job??

[lordedmond]

Andrew

Look here

http://www.irrigationonline.co.uk/black-armaflex-rubber-pipe-insulation-lagging-13mm-wall-thickness/

They have it up to 4 inches on the drop down list to bulk it up one inside the other


Stuart

[awemawson]

Bertie, I've been thinking of slit pipe insulation with one bit entering the slit of the other to form a sort of figure of eight - the installation issue though I think is the real issue. If it is just a sausage in (say) 1 metre lengths I can temporarily pin it to a long pole and poke one end in place, then work along shoving the rest into the gap (there are light fittings and things to work round stopping me using one long length. It needs to be a good 'shove fit'  (engineering term !) so it doesn't all fall out in a high wind

If I could find some 6" thick durable foam (polyethylene maybe?) sheet and cut 6 x 6 bars that would probably do

[awemawson]

Andrew

Look here

http://www.irrigationonline.co.uk/black-armaflex-rubber-pipe-insulation-lagging-13mm-wall-thickness/

They have it up to 4 inches on the drop down list to bulk it up one inside the other


Stuart

Now that's pretty close in the 4" size with the 1/2" walls giving 5" 

But £17  metre  I only need about 18 metres or so so there £300 gone bang    Now how much heat am I loosing and how much does £300 buy 

[DavidA]

Using polythene sheet, roll up some glass fibre loft insulation into sausages and stuff it into place.  Then foam fill the gaps.

You can make the sausages any diameter you want.

Dave.

[DMIOM]

Andrew,

Do you clip your own flock? if so, do you have any of the hessian wool sheets we use to pack the fleeces in? - if so, a few of them split & cut could produce the material for a non-slippery sausage skin - just stuff them & tack with a sack needle & binder twine. Filling - could be fibre glass or straw or hay?  but what do you get for wool....?

Dave (IOM)

[awemawson]

Dave and Dave,

All good suggestions,but this all needs stuffing in on the end of a 15 foot long pole - can't get close enough to squirt squirty foam in there

Yes the wool goes for peanuts - in fact I give it away to a friend who has many more sheep than I, as it costs more to get it to Ashford (the local collection point) than I get for it. 'Wool sheets' (sewn into bags) are man made like jumbo bag material these days. Though I do have some Hessian sand bags thinking about it. (used to patch up bridge revetments - fill with dry mix concrete - it sets when it gets damp, and the bag rots away leaving a not unattractive finish.

(Sheering is set for 1st June if anyone wants a laugh - extra hands always welcome)

[nrml]

How about placing a strip of foil backed bubble wrap insulation over the gap and pinning it to the foam with barbed plastic nails or sticking it with double sided tape? It should be easy enough to do with poles if you divide the length into small segments.

[awemawson]

Well certainly that's a fresh approach I hadn't considered 

Keep those ideas flowing 

[Swarfing]

Why not just use a longer piece of tube to squirt expanding foam? You could use aquarium air line, use some copper pipe which is rigid to thread the tube up. If you can get to both ends then you can secure the tube then pull the copper out. Squirt foam withdrawing the tube as you squirt...simples

[wgw]

I'm a bit confused here with the "top hat" vent. Is this meant as a permanent vent for the shed? I f so and you really want to close it , can you get up outside and seal it ?

[awemawson]

Originally built as a cattle shed it needed good top ventilation, I need far less. My machines don't transpire like cows Sealing from outside is theoretically possible with squirty foam, but when we did this on a lean too at the side of the barn, it wasn't entirely successful, and over a year or two the foam degraded to an unsightly brown colour.

If access up there inside was possible I might try squirty foam, a bit at a time bridging the gap over a few sessions, but trying to bridge that size in one go is asking for it to droop out  - been there done that 

[lordedmond]

Andrew

Look here

http://www.irrigationonline.co.uk/black-armaflex-rubber-pipe-insulation-lagging-13mm-wall-thickness/

They have it up to 4 inches on the drop down list to bulk it up one inside the other


Stuart

Now that's pretty close in the 4" size with the 1/2" walls giving 5" 

But £17  metre  I only need about 18 metres or so so there £300 gone bang    Now how much heat am I loosing and how much does £300 buy 

Andrew
But you did not mention price
Stuart

[NormanV]

What about using 6" square foam strips instead of round? That should be easily available from foam suppliers. I used to work for a company that cut foam to size for packaging using a large band saw.

[awemawson]

Still got contacts Norman?

I can only find 4" and then only the 'upholstery' type which rapidly crumbles away to dust - there is a white firm foam used in some packing that I  'think' would be ideal - not sure what it's composition is but again 'I think' it's "None cross link Polyethylene cushioning foam" according to this web page:

http://www.foampackaging.co.uk/materials/stratocell-foam/

Now - anyone got a big sheet of that 6" thick ........ 

[tom osselton]

Just a thought, If you just plug the inside wouldn't there be a problem with pooling water damaging walls, or mold?

[chipenter]

I used to cut Celotex to size with a hand saw , it's avalable in up to 200mm thick sheets at £80 a sheet its not cheep , and the dust is full of static and seems to follow whoever dose the sawing .

[Pete.]

Jablite polystyrene is available in almost any size. I've used 8x4 sheets 3 foot thick by the lorry load before. Cut with a saw/hot wire to any shape you want.

[Zadig]

I'm struggling to picture the scene, but could you get away with strips of Kingspan?

[awemawson]

Yes if I could get at it, it's access that's the issue

[PeterE]

Hmmm, sounds like the access is the main problem here. You mention that your machines are in the way for more easy access to the roof and that the height is about 15 feet (~5m). So how to get above the machines ....

Would it be possible to re-arrange some of the floor space occupants so that you can use a smallish skylift??? That way you can get close enough to stuff a suitable material into the apex opening and move along with the work. The type of skylift I am thinking about is this:
http://www.heri.se/content/images/thumbs/0000087_skylift_omme_1250.jpeg (one of many swedish places to hire one). This would be able to reach above stuff on the floor provided that there aren't too many awkwardly placed pillars and you would be able to work at a much better working height.

As stuffing material I would use thickish glass or rock wool folded once and pushed  into the opening using a piece of plank.  A roll is 60 cm (2 feet) wide - at least here in sweden -  so cut in half  the 30 cm strip would be quite enough to push into the opening..

Just as yet another idea.

BR

/Peter

PS: I am thinking of using one of those skylifts myself to paint one of the gables on my house as the lower section between the garage and the house see image below gets in the way for simpler scaffolding, and using a lisft is way safer than a ladder contraption - I think.
http://i577.photobucket.com/albums/ss219/H0n3/Homework/garagegavel.jpg
The trick is to get above the lower roof above the windows. DS

<Edited for better clarity - I hope>

[awemawson]

Trouble is some twit put 4.5 tonnes of Traub lathe slap bang in the way of EVERYTHING