Log Cabin Wall Insulation

[john_pullen]

Hi. I have purchased a log cabin (Finnforest Valko) that I will be using as a garden office. I want to insulate the walls and what I have in mind is to use glass fibre type insulation and plasterboards. My questions is on damp proofing and condensation problems. Should I use a damp proof membrane on the inner walls of the cabin or will that cause condensation problems?

Any advice much approciated.

Thanks.

John.

 

[noseall]

i would be more inclined to use a rigid insulation, i.e kingspan or cellotex, as this will have better insulating properties.

there are some fairly good insulation backed plasterboards out there that may be worth an inquiry.

 

[Deluks]

According to this site:

"log cabin is also available with underfloor hating"

Possibly a family of right-wing skinhead voles.

Anyway, from the description it seems pretty weatherproof, although a layer of some kind may be useful in case of any ingress.

The correct sequence would be:
plasterboard -
vapour barrier (can use foilback plasterboard instead but polythene will be cheaper) -
insulation -
breathable membrane -
external walls

This lot should set you back a couple of hundred quid, but well worth the expense if you're using it as an office.

 

[john_pullen]

This has been very helpful. Thanks. I was considering using insulation backed plasterboards. Can I simply screw these to the log cabin with no other membranes or barriers?

 

[noseall]

screw them to the cabin walls with a breathable membrane sandwiched between.

 

[john_pullen]

I like to thank everyone that replied but I have a couple of questions that are hopefully yes/no type questions.

1. What does a breathable membrane actually do? I have tried to search the internet but can't find much. Is it just a waterproof barrier and will it help with damp and condensation?

2. I will be using my cabin as an office so there will be computers and other electrical items in the building. My main worry is condensation. From what I have read the insulated plasterboard would be a good option and I have seen these before but from what I remember they are plasterboards with a polystyrene backing. Does the polystyrene act as both insulation and vapour layer?

3. I plan to use polystyrene floor insulation. Should I use the breathable membrane on the floor?


Thanks again for any help.

 

[noseall]

1. What does a breathable membrane actually do? I have tried to search the internet but can't find much. Is it just a waterproof barrier and will it help with damp and condensation?

you have answered your own question. yes, it is meant to let moisture saturated air out but not let any water in.

Does the polystyrene act as both insulation and vapour layer?

no

3. I plan to use polystyrene floor insulation. Should I use the breathable membrane on the floor?

don't use breathable membrane for the floor. use 1200 gauge polythene.

Thanks again for any help.

 

[john_pullen]

Does the polystyrene act as both insulation and vapour layer?

no

Sorry, one more question on this. Nosall, you recommended insulated backed platerboard. Is this the polystyrene backed type and would it be good enough to keep out condensation with the breathable membrane?

Again, thanks for the input. Much appreciated.

 

[noseall]

there are differing thicknesses and densities of inso' boards.

i think the polystyrene backed board is the weakest and cheapest.

the denser styrafoam type will have the greatest thermal resistance.

look here http://www.bpindex.co.uk/manf.html?id=2239.