Materials to insulate summerhouse & preserve inner timber?

[fluff48]

Hi
I have seen a few threads re insulated summerhouse but I’m looking for a breakdown on what materials would be best.

In particular I’m concerned about ensuring no condensation gets behind insulation onto the outer boards. DD will be in this all winter as a craft room for Uni during day & evening so trying to reduce energy costs & keep warm.

We have 60mm framing and I’m looking at applying the following in this order:

1). One of these treatments applied to the timber panels internally:
permagard/dual-tre...SABEgLxR_D_BwE
permagard/universa...o-use-5-litres

2)do we need this stuff & how is it fitted eg can I staple onto the framing next to the outer panels & should it be tight fitting?
travisperkins/brea...E&gclsrc=aw.ds

3) 19mm pressure treated timber batten applied to create an air gap of 20mm.

4) 40mm insulation board pushed into the framing against the batten above.
onlineinsulation-sales/4...200mm-13-p.asp

5) foam applied an any gaps then edges sealed with foil tape.

Does that seem like a logical order? Any comments on what treatment to treat the inner walls & in Tyvak membrane is needed or any cheaper makes.

Thanks
Fluff

[fluff48]

Has anyone done this DIY or know if the materials I’m going to use are correct? Tried YouTube but there are conflicting ways to do it.
Thanks

[rsvdaz]

What is the internal and external cladding/lining?
I would suggest a Vapour Check Layer (VCL) internally and a breather membrane externally
So for example going inside to out
Plasterboard or t&g boarding
VCL
60 mm studs / framing with 40-60mm Celotex type insulation ( or kingpan or xtratherm ) between studs
Breather membrane (Tyvek Supro)
Battens
External cladding

[scotgirl]

A lot of articles warn against insulating a summer house. We've had one for four years now and use it all year round. We bought an oil filled heater and leave it on low during the winter and turn it up when we're in it. We also have an electric heater that looks like a wood burning stove that we can use for extra heat if needed. Neither of which significantly impact our electricity costs. We also bought a large rug that covers most of the floor. I would be very wary of condensation issues. Shame to spend all that money and then create issues that may ruin it. This is obviously just our personal opinion and experience though!

[Lumpy]

We used the insulation that is used in aircraft and never had any issue with condensation and had summerhouse for around 10 years now

[fluff48]

Originally Posted by rsvdaz

What is the internal and external cladding/lining?
I would suggest a Vapour Check Layer (VCL) internally and a breather membrane externally
So for example going inside to out
Plasterboard or t&g boarding
VCL
60 mm studs / framing with 40-60mm Celotex type insulation ( or kingpan or xtratherm ) between studs
Breather membrane (Tyvek Supro)
Battens
External cladding

See more...

Thanks for the advice. Do I fix the Tyvek supro directly onto the external cladding? How tight does it need to be & do I staple it onto the sides of the existing framing as well as the cladding?

External cladding is probably around 19mm weatherboard and the internal lining will be plasterboard.

Ps. Do I not need the fungicidal treatment if putting on the breather membrane?

Cheers

[Fairysparkled]

Can you give more details of the summerhouse. Size, windows and doors, roof shape, what is the floor sitting on. Is there electric. How far from the main property. Is the roof, walls and floor all timber.

[fluff48]

Originally Posted by Fairysparkled

Can you give more details of the summerhouse. Size, windows and doors, roof shape, what is the floor sitting on. Is there electric. How far from the main property. Is the roof, walls and floor all timber.

See more...

-Approx 3.7m x 2.85 m rectangular footprint.
-Max roof height 2.39m
-All timber cladding floor/roof/wall with pitched roof.
-Not sure what the floor is sitting on as there is a wood finish round the bottom.
-Front is mainly double doors plus a large window either side (around 1.2m) & these take up the full front width (with glass).
-Another two windows on either side of s/house @0.6m each.
-electricity supply already in situ (bored through framing internally) but SIL (electrician) will fit refit on exterior of plasterboard in conduit or similar, so no issues with cladding

[Fairysparkled]

OK, so it looks as if the original structure is well made.
As a plasterer and was doing it for myself and not wanting to spent to much on it. I would not touch the outside, the inside would be boarded with 12mm plasterboard that has polystyrene already attached to it. The ceiling if there is space I would insulate with rockwool and plasterboard it. If you attempt it yourself any gaps and screwheads use easyfill. The floor I would underlay and lay a cheap carpet.
A plasterer and mate would board and skim this in easily 2 days. Costs £700 Cash, plus materials.

[Mexy02]

Our summer house is 6m x 3 m and only insulated floor and roof . We would get wood rot from condensation etc if it was further insulated as the wood needs to breath and expand . We were told not to touch walls at all , one for natural expansion and too the building wouldn’t breath . The building is very warm and we have a small electric fire but the window is opened daily for air circulation . The outside is protected with sikkens so watertight from the outside .