External insulation for a small out building

[glock339]

Hi I have a tiny utility room which has been stuck onto the back of my house many moons ago before I bought the place. Its single leaf brick and obviously freezing in the winter which also makes the bathroom it connects onto a bit cold! Hope this makes sense:

Back wall it a party wall with next door

Front wall is in my back yard

Right hand wall is connected to my house

Left hand wall (solid brick) is connected to my back yard wall so the back lane is on the other side of it.

So I was thinking of internal insulating the solid left wall as I obviously can't external insulate in the back lane. However as the room is so tiny to begin with, I'm really pushed for space so would rather externally insulate the front wall that looks into my yard if possible to allow me to still squeeze in my washing machine etc. The wall in question is only 2500mm long by 1800mm height. Would it be possible to use some sort of insulation and cladding on this little wall and if so what is recommended?

Cheers.
Gary.

 

[abuildingsite]

There are plenty of products out there. The one I see most often is Sto render (although external insulation isn't common at all). However, I'm not sure how effective insulating one wall will be, presuming that your floor and roof are also uninsulated.

 

[glock339]

Yeh I should have mentioned I will be putting on a new roof & doing the floor. Only 2 of the walls are external, 1 of which I will have to bite the bullet & internal insulate, the other I'd like to do externally otherwise I defo won't have enough space for what I would like to put in the room.

I'd rather not have to get a company in for the sake of a 2500 x 1800mm wall, is there a diy solution? Insulationt to existing wall then upvc cladding or something? I realise this could open up a can of worms regarding damp etc which is why I'm asking for advice on here.

Cheers again.
Gary.

 

[Deluks]

One way would be fixing insulation board straight to the walls using long screws through battens, breathable membrane, upvc or timber cladding. Or use Rendalath. You could also fix expamet to the inso and render into that.

 

[glock339]

Thanks for the reply

So am I correct in thinking the breathable membrane will go on the "warm side" as in internal insulation? Or in other words membrane onto wall; then insulation onto membrane and wall; then battens onto insulation and membrane and wall; then cladding over the lot? Or have I got anything wrong?

Would something like king span etc do for the insulation and is there any particular membrane I should use? Also would I need some air vents in the cladding to act like air bricks? Sorry for the daft questions but I've only ever tried internal insulation before!

I was thinking of upvc cladding for easy instillation & weatherproofing. Then hiding the ugly upvc with a nice looking flat wood cladding that I fancy that would not actually be weatherproof, just purely for aesthetic purposes.

 

[Deluks]

I was thinking of upvc cladding for easy instillation & weatherproofing. Then hiding the ugly upvc with a nice looking flat wood cladding that I fancy that would not actually be weatherproof, just purely for aesthetic purposes.

That's insane! Your timber cladding will be weatherproof, of course it will require maintenance every few years but it's well worth it instead of using upvc.

Breather membrane goes on the cold side of the insulation. Over the insulation and under the battens that the cladding is fixed to.

Here is the deal, slighty fiddly batten arrangement in the pic. You could just put boards straight onto the wall and secured with long screws through vertical battens.

The room should be ventilated as normal, either an airbrick with a hit n miss vent on the inside, trickle vents in windows, or mechanical extraction if a kitchen bathroom or utility area.

Don't forget to stop work when you reach the damp proof course.

 

[glock339]

Ahh a pic is worth a thousand words!

Thanks very much for that, I've hunted about but couldn't find one anywhere! Where is it from, do you have a link?

Think I have an idea what I'm up to now anyway, CHEERS!

 

[Deluks]

Just googled it...

http://www.regencyconstruction.co.uk/Insulation.html

 

[glock339]

Spot on

 

[mointainwalker]

@Deluks

What is the pupose of a breathable membrane in this scenario ?

 

[ajrobb]

http://www.celotex.co.uk/Applications/Wall-Insulation/Solid-masonry-walls-External

 

[mointainwalker]

@ajrobb

If the link was meant for me, it left me no wiser.

 

[Deluks]

Probably the same reason you use it on a roof, over the insulation and under the cladding (roof tiles)
Were the cladding to become breached through either damage or extremes of weather, you still have a barrier protecting the insulation from moisture penetration at the joints.
You could probably omit it. I wouldn't.