Kitchen presses and xtratherm boards

garlad

Hi.
Taking a kitchen out to insulate solid block kitchen extension with no insulation.
Builder putting up 3@ xtratherm boards.
These are plasterboards with a 2.5"-ish thick layer of insulate.

Question I have is, whats the best way to rehang the top presses?
Should I screw through into concrete?
Or is there any strong rawl plug type option?

Thanks

RKQ

There are a number of special fixings on the market, each with varying sucess.

Have you considered fixing a timber batten to the wall, to receive the wall units?

As you know where you will hang the wall units, it might be a good idea to install timber battens to fix to. Same for curtain poles, single shelves etc.

garlad

RKQ,
Thanks for that. Was thinking wooden battens would be the best.
Screw them to wall, then cut sections of the foam out so boards can be stuck to wall with battens 'in' them
Cheers

Carlow52

garlad wrote: »

RKQ,
Thanks for that. Was thinking wooden battens would be the best.
Screw them to wall, then cut sections of the foam out so boards can be stuck to wall with battens 'in' them
Cheers

Cannot recommend this approach for 2 reasons.

1, it wont be done with the degree of precision required to make the slot in the insulation exact: the builder will gunter out a big wide slice.....
2 the batten will act as a cold bridge from the solid wall and attract condensation: rem the rest of the wall will now be warmer so the cold bridge effect will be greater
What would work is the following:
instead of the 60mm on the board, go for a 30mm sheet of insulation and then the composite.

put up 30mm battens where you want then and carefully fit the sheet around it: filling any gaps and then tape over the joints.
Then over lay the composite , fixed to wall with mushroom fittings.

You will have similar issues with sockets etc

More work I know but a better job

garlad

Makes sense Carlow52. Cheers.
Issue is that we have the boards bought already
They are too big to bring back to suppliers

Carlow52

Okay then consider the following: which depends on the presses.

Fit the sheets as planned and then mark out exactly on the wall where the presses will be.

Then fix a sheet of say 6mm wbp ply onto the plaster board with the usual pb fixings, the over all size will depend on what you do as per my ideas below and then fit( screw/glue say a 15mm by 25mm slip along the bottom of the wpb which will support the bottom of the presses.

a light alu angle will do also, less visible

The top of the presses can be fixed in a similar way with an angle: therefore the wpb will be oversized hight-wise vs the presses by what ever u do.

the vertical edges of the wpb can be hidden with a corner bead.

ps I have done this a number of times and the top bottom angle or beads are not noticed once the job is done

RKQ

Carlow52 wrote: »

1, it wont be done with the degree of precision required to make the slot in the insulation exact: the builder will gunter out a big wide slice.....

2 the batten will act as a cold bridge from the solid wall and attract condensation: rem the rest of the wall will now be warmer so the cold bridge effect will be greater

Carlow52 gives a good detail, in an ideal world. Point 1 might be a little unfair to some Builders.:)

I wouldn't worry about a cold bridge caused by a timber batten to a wall unit or curtain rail. You won't notice it compared to your existing uninsulated kitchen. You can only do so much with refurbishment, life is rarely Textbook perfect.

Carlow52

RKQ wrote: »

You won't notice it compared to your existing uninsulated kitchen.

The physics is important here.

In an uninsulated room there are few concentrated cold bridges.

This can be shown with thermal imaging

In an insulated room, particularly a kitchen with loads of additional moisture, cold bridges are more of an issue because the insulated room sustains a higher temperature and thus the air retains a higher degree of water vapour.

This water vapour has less options to condense out and the unventilated area behind the press where the battens are fixed will be an ideal spot..

I accept 100% that refurb is not an ideal canvas for implementing such ideas but its important people understand the pros and cons.

The builder is looking at 3 sheets of composite, a few dabs and he is done:)

garlad

Thanks guys.
Plenty to think about over the weekend !

RKQ

Carlow52 wrote: »

This water vapour has less options to condense out and the unventilated area behind the press where the battens are fixed will be an ideal spot..

True but not a problem. The same can be said for the reveals to the window & any external door. The amount of timber batten required to hold one or two wall units is going to have a minimal affect on the insulation value of the whole wall.

Of course the OP could retain a thermal image survey for circa €500 to see this minimal impact!:D Seems a lot of worry, torment and expense over a very small issue.

Glad to be of help garland, have a good weekend. (I'm off to the beach now)