Sealing a Waney Edge Clad Garage/Shed

[kinger251285]

Hi

I am new here.

We moved into a property over a year ago.

In the garden we have a large garage shed. Wooden on a firm concrete structure. It is clad in waney edge wood and has blue plastic sheeting between this and the interior frame.

Some of this blue plastic sheeting has some holes etc.

I want to insulate the garage and then board it out so it can be used in part as a garage/games room/ office. However i need to know how to make it completely sealed before putting up the insulation?

As i said there is waterproofing in the way of the blue plastic sheet on the outside of the frame and between the waney edge cladding however i want to make sure its 100% watertight and a bit unsure how to proceed.

I have never noticed any leaks in the garage to date but want to be extra sure its sealed.

 

[r896neo]

In short you can't be sure without removing the cladding and refitting a new membrane.

Your ideal wall make up from outside to inside is

cladding- battens - breather membrane- plywood sheet-insulation between studs-internal finish ofplywood or plasterboard etc.

Trying to do anything from the inside may be a bad idea as the blue sheet sounds like a plythene damp proof membrane rather than a breather membrane and trying to work from the inside with new membranes could leave you with damp and condensation inside the wall