Discussion in 'Builders' Talk' started by tonynoarm, Nov 12, 2006.
did you read this entire thread ?
Way hay 200+ posts on insulating a conservatory roof, must be a recond.
how much more detail can there possibly be
Well, you missed out a capital and your full stop.
Dan, niiiiice timberwork. Wooo, awesome wallpaper too.
You are going to line the roof with your cladding, so no exposed - cough - 'beams'?
Peasy. Remove all the p'board (sheeesh), and line it all (ie: tack sheets to the undersides of these rafters - don't bother fitting anything between them; leave these spaces for ventilation above) with Celotex or Kingspan or just Jablite. In whole unbroken sheets as much as possible. You only need thinnish stuff - 25mm or 35mm will do.When combined with your wood cladding, this will be well cosy.
Take the sheets right down to the wallplate, mitre to sit snugly against the 'plate, and tape to seal. Tape all joins too.
Job's a jobbie.
(Don't forget to mark where your 'rafters' are before you cover them with insulation...)
Let us know what's behind that plasterboard when you remove it - looks scary.
Thanks for the helpful replies and the unhelpful ones really aren't needed! Yes I'm planning on covering the "beams" and the wallpaper wasn't our choice, decorating usually comes after any remedial works! And wallplates I haven't got a clue what these are! My intention was to glue the bubble foil directly to the polycarb or staple to beams then kingspan insulate level with bottom of "beams" before cladding over the lot! I'm going to remove plasterboard this evening and see what if any insulation is already present.
A wall plate is the beam thats at the top of the windows and under the roof.
Forget the bubble foil just insulate with kingspan or what ever brand you choose, do this as suggested above by covering the roof rafters/beams and then board over.
yep forget bubble foil - if you want to save some space you a proper multifoil such as YBS Superquilt
Ok points noted, if I forget the bubble foil is it worth ensuring the kingspan etc has a foil side?
Also I'm estimating I have atleast a 100mm recess from the beam to polycarb roof so space wouldn't be much of an issue.
Where would the air gap be more beneficial? Between the polycarb and the insulation or between the cladding and insulation?
Yes use foil backed insulation board, air gap between existing roof and insurlation board.
Ok thankyou very much for all your advice I'm a lot more confident in going forward now.
Wow, Dan - these rafters are 100mm deep?
Once you remove the existing p'board, it might be tempting to try and stuff some insulation in between these rafters as it looks like a wasted space. But, if you don't want condensation forming up there - which could ultimately start to rot your rafters - you really want to keep a ventilated gap up there which you keep completely separate from the room below by the insulation lining you'll be adding. Celotex and Kingspan have foil already on them on both sides, so all you need to do is tape the joins and where it meets the walls.
If the upper roof is polycarb sheeting, it's likely to be a wee bitty draughty at the joins and where it meets the tops of the walls. That's good - you want a trickle of air up there. That will keep these rafters - once you've covered them over - completely dry should any condensation try and form.
So, keep it simple - remove all that p'board and stuff, fit whole sheets on to the rafters using a few nails or screws just to hold them in place, and then over-clad.
You don't need thick stuff at all - if you use, say, 25mm thick Celotex, you'll be able to pin relatively easily through the cladding, through this insulation and into the rafters. So dead easy job. (And the cladding will add a surprising amount of insulation too...)
We are nearly there
Thanks devils advocate,
I was planning on cutting the insulation board down to fit perfectly in between the rafters, but I see it makes more sense to leave up full sheets, seal with tape and mark the rafter positions on the board.
Would you suggest starting in the middle and working down?
Glad mine isn't a PVC cony I don't think my misses would be letting me attach wooden beams to a plastic roof
But good job so far looks impressive.
With 100mm deep rafters, you could get away with fitting the insulation in between them as you suggest, but I feel it's always better to overlay in whole sheets where possible.
Pros of using whole sheets:
You'll have an even layer of insulation, with no possible 'cold bridges' where the rafters would touch the cladding (tho' with wooden cladding itself being a good insulator, I guess this wouldn't be a problem in your case.)
You won't risk having 'cold bridges' where the sheet wasn't cut neatly to fit tight between the rafters.
Slightly less chance of having condensation forming up in the rafter void dues to larger air space.
Easier to fit.
Pros of fitting insulation in between:
With the rafter edges still showing, it'll make it easier to pin your cladding to them.
Shorter panel pins needed to secure cladding
It doesn't matter where you start fitting, tho' I suspect it would be easier to start at the wallplate (thanks Phil!). Much easier to cut and fit that mitre without also having to worry about fitting that panel in with the sheet above. But, really, I can't see much difference.
I'd like to have that wallplate mitre neat, tho'. If you slide the sheet (or an off-cut if the sheet is too big to handle) down the rafter until it touches the wall, then use a spacer block to hold a saw blade away from - but parallel to - the wall, youi should be able to mark/slice into the sheet at the correct mitre angle. Remove sheet, draws lines along both sides as your guide, and use either a long-bladed craft knife (less messy, and cleaner cut) or a saw to cut that angle along the edge.
With that sheet then in place - hopefully snug against the wallplate - use the proper tape to seal it against the wall. If you take the tape just a half-inch down the wall, the wood cladding should hide that edge.
Just a quick update I pulled the plasterboard down to reveal just a polycarb roof! No insulation whatso ever!!
That's awesome, doooooooooooode
Would you recommend insulation batts minus the foil?
Just trying to reduce costs or is the foil a necessity.
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