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Need to replace cladding...
David Jenkins - 19/2/21 at 03:35 PM

...but, as usual, I want to be awkward!

Currently we have wooden cladding in several places around the house, and it's a regular maintenance PITA. It really needs replacing with uPVC, but there is another issue - cold walls and drafts.

Although our house has cavity wall insulation, I am fairly certain that it didn't get behind the cladding so those bits of wall get quite cold. Also, in one or two rooms I can feel drafts around my ankles in high winds. My cunning plan is to fill the spaces between the support timbers with insulation once the old cladding has been removed (or, at least, get the cladding firm to do it).

Now here is my question: what is the best insulating material to put in the spaces, and should there be a membrane like Tyvek over the top before the new cladding if fitted, to keep the insulation dry?

Basically, when I ask for quotes I want to have a reasonably informed discussion with the bod who does the estimate, and I want to avoid the "3 Bs" (Bullsh*t Baffles Brains).

Any clues on the current best practices?

roadrunner - 19/2/21 at 04:54 PM

Afternoon David.

How thick are the batterns.
Best insulation is Celatex, then rock wool, even polystyrene but I wood avoid that for fire reasons.
Would definitely put a membrane over the insulation to keep it dry. Wet insulation is useless.

Have a look at Canexel cladding. Better than PVC as it won't creak when sun comes out on that day in summer.
Canexel is a pressed hard board and you can get it in most colours. We use it on our caravans.

Brad

[Edited on 19/2/21 by roadrunner]

jimmyd - 19/2/21 at 06:08 PM

Most forms of insulation will make a big difference, I recently used and recommend rock wool but after insulation you need a breathable membrane then air gap then cladding, I’m assuming this is timber frame. Lots of good information on line if you look at building regs or even suppliers like Kingspan.

Mr Whippy - 19/2/21 at 06:24 PM

Another for rockwool, basically lava candyfloss. Totally fire proof and safe to install, although I still wear a mask. I'd stay away from any using recycled plastic bottles etc.

jacko - 19/2/21 at 06:57 PM

David can I suggest you have a look at a web site
The Garage journal

There is a lot about insulation /cladding etc
Graham

David Jenkins - 19/2/21 at 07:05 PM

Thanks to all - some good starting points for research there.

Smokey mow - 22/2/21 at 09:10 AM

The batten cavity should not be filled with insulation. It is there to provide a ventilated void to remove moisture and condensation. If you fill the depth of the battens with insulation then the dew point of the condensation occurs within the structural frame which will ultimately lead to mould and rot.

Deckman001 - 22/2/21 at 01:06 PM

quote:
Originally posted by Smokey mow
The batten cavity should not be filled with insulation. It is there to provide a ventilated void to remove moisture and condensation. If you fill the depth of the battens with insulation then the dew point of the condensation occurs within the structural frame which will ultimately lead to mould and rot.


The above is what I was told by a council Building regulator when i asked about insulating the void between the lathen plaster ceiling and the roof first boards under the tiles. I had assumed i could fill between the joists? with insulation to make it warmer, but he said NO! that space is seriously needed to avoid any moisture build up, so I would have to loose a few inches off the ceiling height and sections of similar walls to insulate the walls/ceiling by just adding insulation to what is already there.
This is sadly no information on what to use, just a friendly warning of how not to do it

Jason

roadrunner - 22/2/21 at 01:53 PM

That's why you use a breathable membrane then place another battern on top for the cladding.

Smokey mow - 22/2/21 at 06:10 PM

quote:
Originally posted by roadrunner
That's why you use a breathable membrane then place another battern on top for the cladding.


If you add an extra batten over the top to create a new cavity then that’s ok, but I read the OP that they were going to remove the cladding, fill the batten cavity with insulation and then fit the cladding to the original battens without providing any new cavity.

[Edited on 22/2/21 by Smokey mow]

David Jenkins - 22/2/21 at 06:21 PM

No, I hadn't made my mind up about anything! I was looking for info so that I can have a sensible conversation whichever company fits the cladding.

A the moment, the best option looks like filling the cavity with something like rockwool, covering it with breathable membrane like Tyvek, battens on top then the cladding. But this will be the subject of discussions when I shop around for a quote.

roadrunner - 22/2/21 at 11:10 PM

Isn't there quite a few companies in Suffolk who specialise in timber clad construction.
I had a dirty weekend down there a few years back and noticed a lot of timber houses/garages and extensions.
Made me think about setting up my own business.