Timber summer house help

[Rob Evans]

Hi
I’m new here so hello, obviously I’m here as I’m looking for some help

I’m currently building a timber frame summer house my Mrs now wants to put a lazy spa in there and I’m getting worried about condensation

I will be putting a xpelair in the summer house to hopefully help a little

My build so far consists of
22mm cladding
100mm timber frame
Into which I was putting 100mm celotex
Then I was thinking a breathable membrane
Then 6mm wbp painted with a gloss paint

Is there anything else I should be doing?

Thanks rob.

P.s be gentle it’s my first build

 

[^woody^]

You're doing enough. But there is normally osb or ply sheathing on the outer side of the frame onto which the membrane goes between the cladding and the frame to keep water out, and the cladding is on battens. Foil tape the celotex joints.

 

[John D v2.0]

is that outside to in or inside to out that buildup?
you'd need a breathable membrane on the outside to protect the timbers, and some kind of vcl on the inside e.g. poly sheet. Celotex is pretty good, but in a high humidity environment it's more important to be thorough.
You'd also need to cover the studs with a thin layer of celotex to stop thermal bridging and getting condensation on there in winter. Wood isn't a great insulator compared with celotex.

 

[Rob Evans]

Outside to in

The timber frame is made from 8x4 plasterboard pallets with the cladding on one side. I intend to fill the cavity of the pallets with 100mm celotex which I have not done yet so I’m still in a position where I can add the breathable membrane before the celotex

Is there anything I can do with the roof to help get the moisture out

Sorry for being an idiot but the Mrs has taken over my man cave with this bloody spa idea and I’m not sure what to do now

 

[motorbiking]

You won't get 100mm of Celotex in a 100mm timber frame - I made that mistake. Your 100mm beams will be approx 96mm which is just enough to stop you. I ended up having to put strips of 6mm ply on the beams before plaster boarding.

 

[John D v2.0]

Sorry for being an idiot but the Mrs has taken over my man cave with this bloody spa idea and I’m not sure what to do now

jut tell her the good folks of diynot said the shed will rot if she does