Widen Stud Walls

[Rexyboy]

Looking for a bit of advice on the best way to widen a 70mm stud wall. We want to turn two internal walls into 90mm (min) for such things as in-wall cistern, decent niche, shaving cabinet etc. My current plan is to sandwich some 90's to the side of the existing 70's before linings.

Any tips or suggestions appreciated.

Thanks.

[419]

Single strip 20mm packers on one face of the studs gets you there and cheaper and quicker than putting 90mm on the sides of the 70mm studs and cutting 90mm to allow for existing noggins. You'll get 4 x 20mm packers out of 90mm with almost no wastage after allowing about 2 to 2.5mm kerf for the cuts. 70mm studs are presumably in a very old house or non-structural in anything more recent. Would be prudent to check with a builder or engineer that any solution is structurally okay.

[jack620]

I agree that 20mm packers is the way to go. I wouldn’t bother consulting an engineer though. If 70mm studs were acceptable, then 70mm studs plus 20mm packers has to be acceptable.

[Avondale]

Reading your requirements I ask is 90mm enough?
I renovated our bathroom and separate toilet. It had 4"X2" hardwood studs.
I made inbuilt cupboards in both with sliding doors.
The bathroom I made a solid blackwood insert with adjustable shelves and used heavy-duty draw runners to attach the door.
It has a plywood door with toughened mirror. (I've since learnt plywood isn't stable once the sheet is cut. Courtesy of plywood manufacturer! Mine has stayed flat thankfully)

Only mention all that as I wasn't sure what your door plans were
I agree on the packers but I'd check the stud alignment.
20mm just nailed or screwed to existing would follow the curves of existing wall.

My 2 bobs worth

[Rexyboy]

Thanks for all the responses. I think I am now on the same page re packers on the front face. It would be nice to have a table saw but the track saw should get me there. It's a good point about the squareness of the walls. On a previous job I found out the hard way that my walls were not square. Putting the packers on the face may kill two birds with one stone if they are not square.

The only challenge I see is on the internal corners. In one instance I will widen two walls that meet at an internal corner. I guess I may need to sandwich something on the side of that one as the wall will (also) be getting 20mm shorter. Any thoughts on this one?

Thanks again.

[r3nov8or]

In the internal corner you will probably easier to sister/sandwich at least one side. But you could prefab an internal corner.

Packers everywhere else will mean you keep the same opening between studs, so it'll maximise niche width etc

[Avondale]

What are you covering wall with?
On corners, I'd run a vertical strip 20mm out from other wall, on BOTH walls.
If you need to pack the strips I use pieces of floor vinyl, icecream buckets, thin mdf If it's over 2mm,
Those vertical pieces may need backing to prevent movement. Assume noggins aren't very close. 2 max over 2.4 metres
Could just glue offcuts of a stud or suitable thick timber onto end/ corner studs and but against strip.
Make sure what you're gluing to is dust free. I'd vacuum the substrate you're gluing to. And wait for it to properly cure before getting too heavy handed with next stage.

[Ardep]

i packed out a wall using strips, i glued with polyurethane expanding glue (insert brand) and taped them on. I then planed them to make the wall, flat, plum and level.

Installing an inwall cistern (gerberit) is somewhat a new thing for most plumbers (mine included). The instructions are general in nature. I built the framework as instructed and after install realised that:
My studs could have been much closer to the unit. they were set out to 600mm, but the unit is 450 so closer is better for the cladding and firmness of the mount.
The water inlet is in the top and a pain to hook up when the plumber has run the pipe to the usual location.
The set out for the flush plate makes it at 1100mm center. Could be lower.
The piping to the toilet pan depends on the pan, so adjust to suit before adding the cladding. Dont forget to add the flooring, tiles, screed etc.

The moral of our house build is if its worth doing its worth doing twice!! (sometimes 3 times)

[419]

i packed out a wall using strips, i glued with polyurethane expanding glue (insert brand) and taped them on. I then planed them to make the wall, flat, plum and level.

Another and quicker way to do it is to get the existing studs plumb and level, then nail the packers on with alternate nails angled about 15 to 30 degrees in opposite directions to resist pull out. As long as the packers are all the same thickness it'll work out fine.

[Ardep]

i only glued them on because I had to plane them down as the studs were bowed and twisted. I didn't want to cut and cleat 3 out of 4 studs.