Shower wall / high pressure laminate board strength

[DundeeDancer]

I'm having put into an existing bathroom a counter top basin resting on top quartz top sized at 400*500*32 .

 

The weight soon adds up and the wall I've been told is not that strong as it's some honeycomb design with vertical batons every 1200mm.

 

Therefore I'm thinking, probably wrongly, that we could get a single sheet of an MDF shower wall and glue and screw that onto the wall and into the structural timber at ceiling and floor height.

 

That might give something more solid for the basin cabinet to be attached to.  The basin cabinet does have 2 legs to help support the weight above but people will still lean again the basin from time to time causing horizontal stresses.

 

I do worry though that the shower wall type material might not be up to the job of supporting the screws which will anchor the basin unit into the wall and if screws are used and it being a bathroom environment then damp could get in and ruin the panel fairly quickly?

 

Wondering if people out there ever tried something similar or had a better way of approaching this problem?

 

The product I was thinking of using would be something like this:- http://www.diy.com/departments/splashwall-milano-marble-effect-single-shower-panel-l242m-w12m-t11mm/258216_BQ.prd

 

 

Thanks, DD  

[ProDave]

It sounds like you have what I call an "egshell" wall.  Basically 2 sheets of plasterboard about 50mm apart, with a lattice of cardboard between them.  the timber battens will be at the joint every 1200mm

 

Your bathroom counter should be self supporting from the floor. If necessary fit additional feet or a more solid support for the base (assuming it is hidden by a plinth) so all the fixing to the wall does is stops someone pulling it over.  If you can get one fixing into a timber upright  I would have thought that was adequate.

[AliG]

Hi,

 

Nice to see someone else in Edinburgh.

 

That panelling is made to be waterproof not to take weight, it certainly won't hold screws well.

 

It's not clear what you are installing here, you said a quartz top then you said a cabinet. Does the top sit on a cabinet underneath or do you mean a frame that goes back to the wall?

 

Anything supported from the wall is going to need a frame to take the weight, you would probably have to break into the plasterboard and create a frame inside the wall connected to the studs that are there. I have a wall hung double basin and cabinet where they built  a small step into the wall to support it at the back, but again if there is no frame in the wall it will be hard to build something like this with nothing to attach it to.

 

Is the wall going to be tiled? Without more framing, anything wall supported would probably cause the wall to bow and the tiles to pop.

 

Do you have a picture of that you want to install?

[DundeeDancer]

It's an Ikea base unit like the one below, I also got 2 * 25cm legs for it, another 2 legs might be an option but the toiler waste will run under the unit so not much space down there.

 

 

As you can see from the picture above it doesn't come with a top so I got a quartz top made up which must weigh about 15kg.

 

Along with the basin to sit on top...

 

 

ProDave is correct I have heard the builders say it's an eggshell wall, made of panels with little structural supports in them. 

[AliG]

The legs would support the weight, but the issue is going to be what do you screw into and the likelihood of the wall flexing.

 

In all honesty I have never seen this kind of wall.

 

@ProDave is right, if the cabinet can overlap a stud at all then attaching it to one stud should give a tight fixing and you can attach the other side with a plasterboard anchor. However, I am guessing you wouldn't be asking here if that was the case. I have done the same thing fixing a large TV to a plasterboard wall.

 

You could use a plasterboard cavity fixing as it won't actually be taking a lot of weight, but i would be worried about the plasterboard flexing and eventually breaking.

 

I was going to suggest a strip of marine ply to replace a strip of the the plasterboard and screwing into this. The trouble you will have then is attaching the plasterboard to this.

 

Best solution I have is cutting a strip out of the plasterboard. Putting in two noggins that attach to the studs on either side, slip the noggins halfway behind each edge of the cut them you can put a new strip of plasterboard back across the noggins and screw into one of them.

 

No matter what you do you will be left with a decorating job, but I assume that has to be done anyway.

 

 

 

 

 

Edited November 1, 2017 by AliG

[Ferdinand]

6 hours ago, AliG said:

You could use a plasterboard cavity fixing as it won't actually be taking a lot of weight, but i would be worried about the plasterboard flexing and eventually breaking.

 

I wouldn't go there as a primary support. Here we discovered 6 months after moving that that was how our heavy stair handrail is attached like that, when one came out.

 

I spent half a day looking for structure in the wall and found nothing suitable, so I ended up bolting right through the wall and making the 100mmx100mm stainless steel anchor plates on the other side a feature in my office.

 

For this, I think I would build a small custom boxframe from CLS to sit beneath the cupboard, either to the same footprint or slightly smaller to look attractive,  then sit the unit on it and panel the sides with a suitable finish. You may or may not need to drill into the floor to hold the box frame in place, or could fix it the wall with something just to stop it moving. Alternatively you could glue the box frame to the floor. It could go inside the Ikea legs of you prefer.

 

You could even make your box frame from 18mm ply as a simple box. I could also see something like an Ind Coop beer crate that builders stand on working if it is the right dimensions.

 

There is nothing to stop you using bricks or a stack of one or two breezeblocks or thermalites or similar on their side instead of a box frame. You can just hide them behind a trim. If there is an issue attaching the unit to the top of the blocks, then plug a small sheet of eg marine ply the same size as the footprint and screw to that.

 

Ferdinand

 

 

Edited November 2, 2017 by Ferdinand

[Nickfromwales]

What stage are you at with the job? Are you fully refurbishing the room or just changing the sink ?

If the wall panels are going onto the whole wall from left to right and the sink is in the middle then it's a relatively easy fix. Just channel out the PB and egg box from one vertical batten to the next, the ones that span the area the sink is to be fixed to, 1230 high and remove the cardboard lattice entirely. Brush the exposed PB ( rear of PB of the adjacent room ) with 75 / 25% PVA / water and then cut a piece of 22mm P5 Weyroc and lay horizontally, working from the floor up, so two pieces required if one 2400 cut in half won't do the width. 

Get some fast fix ( pink foam ) and apply horizontal and vertical beads of foam at 100mm centres to the PB going only as high as 550mm from the floor first ( 600mm P5  )  Push the P5 against it and gently push against it for 20 mins whilst it cures. It's important to dampen the face of the P5 with the same PVA solution to aid adhesion and speed the cure. Glue the tongue and do the same with the next piece. Then you have a section of 22mm thick P5 say 1200 wide and 1220 high embedded and bonded into the wall void. Measure the thickness you have remaining to the existing PB face, match with the nearest undersized product, 4mm / 6mm ply or better if you can get 9.5mm or 12.5mm PB but either will suffice. If it's ply, glue and screw it on, PB just needs screwing. 

Then apply your wall pannelling over the top and it'll be rock solid. 

 

Edit to add : To remove the original PB from the egg box lattice you'll need to cut it into multiple strips of 50mm and remove them one at a time so as not to damage the other room surface. 

[Nickfromwales]

Or you could go balls out and recess a pair of metal box sections from floor to ceiling and finish those flush to the existing PB. 

[DundeeDancer]

I've suggested to the "Professional Builders"  that I am paying to do this job to maybe consider the following:- 

 

"Maybe we just need to embed into the plasterboard a horizontal strap of structural wood to give some support where the basin attaches to the wall."

 

I shall await their Professional Bull**** response and hopefully I'll find a way to make them see the light to do the job right so it last the test of time and not just past the defect period.

[Nickfromwales]

3 hours ago, DundeeDancer said:

I've suggested to the "Professional Builders"  that I am paying to do this job to maybe consider the following:- 

 

"Maybe we just need to embed into the plasterboard a horizontal strap of structural wood to give some support where the basin attaches to the wall."

 

I shall await their Professional Bull**** response and hopefully I'll find a way to make them see the light to do the job right so it last the test of time and not just past the defect period.

"He who pays the piper calls the tune" . 

[DundeeDancer]

A big THANKS from me to all you guys.

Bouncing the problem in here has really helped.

 

As the toilet waste runs under this unit and needs to be boxed in, if the boxing in is made strong then the basin unit could rest a little on it for extra support.

 

Also to the left hand side there is the main vertical drain that is all boxed in.

So if a 30mm bit of strapping was added to the side of that then the side of the basin unit could be screwed into that strapping and which would add horizontal support, that would take away the need to strengthen the back wall as there so never then be any significant forces on the back wall.

 

Phew, I think we have a solution!

 

Cheers, DD 

Edited November 2, 2017 by DundeeDancer