Advice on french cleats

[DangerousDave]

Hello all,
I'm fitting wall units as part of a fitted bedroom and was planning on using cleats to mount them on the wall. I've never done this before and I'm not sure of a few things :? ;

1. It's a stud wall, can I screw the cleats through the plasterboard into the studs, or do I need to remove the plaster board and replace it with ply for the width of the units? The studs seem to be at approx 400mm centres

2. What sort of timber do I need to use for the cleats, would scrap rough sawn be ok or do I need to use hardwood?

3. Do I need to add additional noggins between the studs where the cleats will be attached?

Any advice would be very much appreciated. Also if anyones interested there's WIP pics
here

Forgot to mention, the carcasses are 18mm MFC and are pretty heavy

 

[wizer]

deffo fit a ply panel if you can. Softwood or even ply should be fine.

 

[DangerousDave]

Cheers, Wizer I'll give that a go

 

[Screw Loose]

This might be of interest

 

[DangerousDave]

Cheers Screw Loose, that site looks good. Don't have time to look at it properly now as SWMBO is yapping in my ear for her to have a go on the computer now :x I'll take a proper look at it when she's gone to bed

 

[Frank Drew]

Dave,

You can leave the plasterboard in place and screw right through it and into the studs, but you'll need nice long screws to get a good purchase. The cleat can be made of anything... scrap soft- or hardwood, ply, whatever, but you might make it wide enough for an upper an lower screw at each stud, for insurance.

A problem I ran into once was that the wall wasn't flat where I wanted to attach the cleat, so I had to shim it out at each end since, of course, the back of the cabinet with cleat was quite straight and flat.

 

[Tusses]

any old scraps will do and through the plasterboard into the studs is fine

 

[Argee]

If I've got a run of cabinets, I tend to use one long softwood French cleat, notching the cabinet sides as required (but not the outermost carcass sides, of course!). For particularly heavy units, I use a double row of cleats and a simple jig to fix the second row to both cabinet and wall.

Ray.

 

[DangerousDave]

Cheers Frank, it hadn't occured to me that I might have to shim the cleats level. Was planning on using 80mm deck screws to attach the cleats onto the studs. I might be better off using a ply backer panel to make it easier to level the cleats :?

 

[DangerousDave]

Ooops, sorry Argee and Tusses, you both posted as I was writing the reply to Frank. Cheers for the info, I guess that using one long cleat makes it easier to make sure its level and plumb.

 

[Argee]

I guess that using one long cleat makes it easier to make sure its level and plumb.

That's precisely why I do it. You can swiftly work out the rough shape of the required notches on the inner sides of the run, then make a cardboard template to draw it onto the required sides before jigsawing.

Ray.