How to insulate a shed roof?

[MagnusTS]

What's the best way to insulate the inside of this shed roof?

I was thinking just Kingspan between the joists and a plywood (5.5mm?) lining.
But how to attach the Kingspan and plywood?

The joists are very deep and I wouldn't want to bring the ceiling down that low.
Would I have to add batons between the joists, Kinspan between those, and screw the ply to the batons?
But once I start adding batons in there there is not much room left for the Kingspan.

Any idea and suggestions very much appreciated. Thanks.

 

[user 18729]

What's the best way to insulate the inside of this shed roof?

I was thinking just Kingspan between the joists and a plywood (5.5mm?) lining.
But how to attach the Kingspan and plywood?

The joists are very deep and I wouldn't want to bring the ceiling down that low.
Would I have to add batons between the joists, Kinspan between those, and screw the ply to the batons?
But once I start adding batons in there there is not much room left for the Kingspan.

Any idea and suggestions very much appreciated. Thanks.

View attachment 40028

I used cheap expanded polystyrene sheets for my shed. I put in a breather membrane, then just used instant grab adhesive to stick the insulation in between the joists

 

[BrewMeHappy]

I'd say something like Kingspan foil faced insulation boards cut so they sit tight between the beams, but polystyrene ones woodwork too as Hopsteep suggested.

Be careful with trapping moisture above them and below the roof timbers though so you may need to add some for of vent to outside and have the insulation such that there is a bit of a gap to the underside of the roof timbers. There are a few videos on YouTube about it, and tips on using vapour barriers too.

 

[MagnusTS]

I'd say something like Kingspan foil faced insulation boards cut so they sit tight between the beams, but polystyrene ones woodwork too as Hopsteep suggested.

Be careful with trapping moisture above them and below the roof timbers though so you may need to add some for of vent to outside and have the insulation such that there is a bit of a gap to the underside of the roof timbers. There are a few videos on YouTube about it, and tips on using vapour barriers too.

Thanks. That sounds like a good plan.
What would be the best way to cover the Kingspan to make a neat finish?

I was thinking using ply cut to size, but what would i fix the ply boards to?
Would I have to tack batons to the beams, put the Kingspan between them, and fix the ply to these batons?

 

[BrewMeHappy]

The easiest way would be to cut the insulation tight and then fix the ply to the roof beams to cover it and stop any insulation ever falling out, but you will use a bit more head height.

I build a garden room a few years ago and put the insulation between the beams and then over clad with 6mm plywood fixed to the beams.

 

[MagnusTS]

The easiest way would be to cut the insulation tight and then fix the ply to the roof beams to cover it and stop any insulation ever falling out, but you will use a bit more head height.

I build a garden room a few years ago and put the insulation between the beams and then over clad with 6mm plywood fixed to the beams.

great thanks. And sorry to ask, but my DIY skills are rubbish, are you just putting screws through the ply at an angle into the beams?

 

[BrewMeHappy]

No, I just screwed straight into the beams not at an angle.

 

[Bill_g]

If you want to preserve head hieght between the beams then I'd be inclined to fit insulation to roof with adhesive or just tight fit, then 6mm ply held by a long batten each side screwed to the beam. This would give a neater appearance and hide any small gaps between the ply and the beams. As has been said a vapour barrier between the ply and the insulation would be a good plan. This could be staple gunned in place or glued (with some difficulty) if you really didn't want any holes in the vapour seal. The vapour seal could be brought down the beams by say 25mm or so and this then covered by the batten, so the staples could then just go into the beams where the small holes would not matter. A fiddley job & a second pair of hands would be a great help.
Assuming this is to be your brewing shed then an extractor would be advisable during the boil because it puts several litres of water into the air.
The other thing that you could consider is to use a multilayer foil blanket insulation. There are several brands on the market. Typically they are about 20mm thick or less and the equivalent of 100mm of polystyreme or similar. I have used this type of product stapled to the roof of a shed and also to insulate the garage door of my workshop It is a very effective insulation material but unfortunately not cheap.

 

[Hazelwood Brewery]

How about fitting noggins between the beams that are the same depth as your Kingspan. You could fit these every four feet or so - the width of the Kingspan. Infill with Kingspan (you can use double-sided carpet tape to hold the Kingspan in place). Screw through the ply into the noggins.

 

[Tanglefoot]

How about fitting noggins between the beams that are the same depth as your Kingspan. You could fit these every four feet or so - the width of the Kingspan. Infill with Kingspan (you can use double-sided carpet tape to hold the Kingspan in place). Screw through the ply into the noggins.

This.

A good idea also as it will beef up the roof ( no rafters ) and prevent the purlins twisting.

 

[MarconiBrew]

If you want is a warm room, after using the foil backed kingspan, consider using plasterboard instead of ply. Use the plasterboard which has 25mm foil backed insulation backing onto it, this will bridge the timbers giving a proper thermally warm room.

 

[johncrobinson]

what the hell is noggins and perlings ,????

 

[Hazelwood Brewery]

what the hell is noggins and perlings ,????

Knitting stitches

Purlins are roof supports that run parallel to the roofline.

Noggins are for bracing, they stop purlins/joists/rafters/studs bowing and twisting.

In this case their purpose is actually to form a hidden fixing point for the ply

Something like this

 

[MagnusTS]

Thanks for all the advice on insulating.

Was also thinking, how big a job would it be to take the shingles off the roof and add a layer of Kingspan to the outside of the roof, and cover with ply (?) and then put the shingles back on.

Another question, sorry: There are gaps where the ceiling meets the walls. Should I be filling these with some sealant to keep the heat in, or are they needed to stop condensation?

It's not going to be a brew shed, so no massive steam problem to deal with. Just for wife's yoga and the boys to use as a gym.

Thanks again everyone.

 

[Clint]

I don't know much but I'd definitely not take the roof off! Insulate from the inside.

 

[Hazelwood Brewery]

Thanks for all the advice on insulating.

Was also thinking, how big a job would it be to take the shingles off the roof and add a layer of Kingspan to the outside of the roof, and cover with ply (?) and then put the shingles back on.

Another question, sorry: There are gaps where the ceiling meets the walls. Should I be filling these with some sealant to keep the heat in, or are they needed to stop condensation?

It's not going to be a brew shed, so no massive steam problem to deal with. Just for wife's yoga and the boys to use as a gym.

Thanks again everyone.

Probably big enough for you to wish you hadn’t come up with the idea!

You’re likely to damage the shingles and felt when you lift them, and the Kingspan is not suitable for fixing ply onto so you will need to create a new structure. It can be done but at greater expense, time, and effort.

If you’re wanting to keep the tongue and groove, you can buy T&G effect MDF and use that rather than ply. It is again more expensive though.

 

[Clint]

I've had a great idea....buy them all some jumpers...

 

[Bill_g]

[

Thanks for all the advice on insulating.

Was also thinking, how big a job would it be to take the shingles off the roof and add a layer of Kingspan to the outside of the roof, and cover with ply (?) and then put the shingles back on.

Another question, sorry: There are gaps where the ceiling meets the walls. Should I be filling these with some sealant to keep the heat in, or are they needed to stop condensation?

It's not going to be a brew shed, so no massive steam problem to deal with. Just for wife's yoga and the boys to use as a gym.

Thanks again everyone.

Draught proofing any gaps and the door will have a much bigger impact than any insulation you may add ... and no don't even think about taking the roof off.
Sheds are only temproary buildings & don't last for ever, They tend to rot from the ground up so overall I wouldn't worry too much about condensation etc.

 

[itry]

This is how I did mine

 

[MagnusTS]

View attachment 40619

This is how I did mineView attachment 40619

Nice. Looks like you've nailed a load of sheep to your ceiling.