New build garage condensation?

[darren6645]

I live in the UK I have just had a 6m x 5.6m detached garage built. If I put a carboard box in after several days it is mush and anything that is currently stored up top on roof trusses is covered in mould. Garage was finished middle of December, single brick consruction, tiled roof no insulation to walls or ceiling, damp proof membrane below 6" concrete floor. The garage is for 1 car plus bikes, storage and work area heating is not an option.

 

[leeco]

What you want is some air circulation or stud the inside out and insulate it with kingspan leaving a cavity.

 

[darren6645]

Soffit vents then to give the circulation is that the answer.
I have just been out and checked the roof is lined with Pro clima INTELLO PLUS i think. (Intelligent vapour check and airtight membrane, features humidity variable diffusion resistance. It gives maximum protection to thermal insulation where moisture entry may have occurred. This may be through leaks, damp building materials or diffusion through adjoining structural surfaces. INTELLO PLUS possesses the world’s best and most effective variable diffusion resistance) from website. Where the roof trusses sit on the walls is a black plastic strip if I put my hand in and lift the membrane I can see daylight so I was thinking that was enough ventilation unless this is dropping in the wind and the air is going up behind it and back out through tile gaps? does that make sense?

Cheers.

 

[leeco]

The thing is the moisture is coming in through the walls and I think this stuff is to stop moisture coming in through the roof and maybe making the problem a lot worse as the moisture has no escape.

Is this stuff under the tiles as I think a breathable felt would of been a better option.

Soffit vents should help and maybe a couple of ventilation roof tiles near the peak of the roof might be a good idea.

 

[darren6645]

Thanks for that Ill have a word with my builder and see what he comes up with before a suggest the above options, just wanted some advice before I asked him but basically what you have said is what I thought.

Thanks again,

Darren.

 

[leeco]

Looking at this vid.

http://www.youtube.com/watch?v=aTdJYcXiTdI

Maybe get some of that stuff on the walls too to stop the moisture.

 

[michaelbailey]

you have 150mm concrete base this should be sufficient to take a cavity wall 100mm thermalite block 100mm. ins ul. sticking something onto an existing single brick wall will not stop condensation
ps don't forget the wall tis