fixing acrylic bath into cradle

i have just recently installed an acrylic bath using 35x70mm timber for the frame.
as the bath was in the corner of the room i recessed the bath into the wall 25mm so the villaboard and lamipanel would sit in front of the bath lip. this also gives a ready made two side of the bath frame
the bath should sit level as they are made to drain when installed this way.

mumu

I installed an acrylic bath about ten years back and did it just how jackrussel said, even down to the lamipanel. One extra thing I did was sit the bottom of the bath in a fairly sloppy concrete mix so that most of the weight when full was transferred straight to the floor. I can't remember if the instructions that came with the bath said to or whether my dad said to, but I did it.
and as jackrussel said, build the frame level, the bath has the fall built into it.

Jon

The bath manufacturer must have an instalation sheet, so definately follow that up. With the mortar bed my understanding is this should be 50mm (2") thick minimum, but silicone should do the job around the bath rim as the base pretty much take the strain, and the framing supports the upper part, you just need to stop the squeek without stressing the bath when it expands and contracts. Goodluck without a sheet its a bit of a pain getting it right.

Wow
Thanks a lot everyone, I had not heard of the mortar base trick.
And I will definitely phone the manufacturer again and press a little harder for information.
Thanks also for the key-word tips, I'd tried 'bath cradle' but it took me to a lot of sites about babycradles that fit in baths. What next?
I'll check the sites.
Would ready-mix concrete or a mortar mix be better if I go this way?

Mortar would be better, you don't need stones sticking up. If you make a slurry make sure it is not too dry or you will not be able to seat the bath properly....

You can also line the floor under the bath where your slurry is going with plastic to keep the moisture in... depends on how sealed your floors are or you may end up with mortar floor in your bathroom.... ;-)

Thanks for that advice flat-Tyre.
I must admit I'm a bit wary of mortar on the timber floors, won't it just flow down the hole where the waste pipe goes? Also the technical stuff I have since found on the web suggests these acrylic baths need to sit flat on the floor for structural support, so if I built an edge around the waste to keep the mortar in, I guess it could be no higher than the little support foot built into the base of the bath .
Now my other main concern is the recess into the wall. My bath is 1675 long, I bought that length because that is the length of the bath that came out.
The bath fits against one side wall of the bathroom, which happens to be a braced load-bearing wall, and between two end walls. The space from stud to stud of the end walls is just shy of 1675 mm too. Obviously, if I recess the bath in one end, it will fall short at the other end. Also I'm not sure if I can safely cut into the load-bearing side wall.
The bath I just removed (which was iron) was butted up to the long wall and in the end walls there are bits chiselled out from the studs at the height of the old bath rim, but they are only a couple of mm deep. (This could have been for a previous bath). The walls were lined with old pinex/ softboard, (1930s) A sheet of laminex then went on top of the softboard, down to about 200 mm above the bath and then a timber plank about 300 wide was glued and nailed into the studs all around the wall, covering the gap between the laminex panel and bath, and forming a 'skirting board'. the joint between the plank and laminex was covered by a wooden 1/4 round moulding, and the gap between plank and bath was filled with silicone.
I now realise the timber plank was probably there to give that additional recess. Would that be right?
Will I need to do the same? I was intending to butt the bath against the wall, then cover the walls with aqualine gib, cut with a 10 ml clearance above the bath upturn, then cover that with seratone (which has a sealed edge extending 150 mm up the back edge, and bring the seratone down into a pvc moulding that goes between the gib and seratone, and then curves down past the upturn to the bath edge, leaving a gap between it and the gib that gets filled with silicone. (This is all as per seratone's technical instructions, except they show the seratone attached directly to the studs).

The plumber keeps raising his eyebrows and saying, mouldings are not reliable and the bath should be recessed.
Any ideas? Should I follow the seratone guide, should i use the plank over the top method, or is it safe to cut into the load-bearing wall (surely not!)
I might mention, when the bathroom was first built there was probably no shower over the bath, but a shower had been installed probably in the 50s, using the method described above. When I took the panels off the wall, there was no sign of any leakage ever, so they must have done something right.

thanks for any advice

my bath sits on the existing concrete floor but instead of using a stiff mortar mix to bed it in i used a couple cans of expanding foam. the bath being very light had to be weighted down(i just turned the tap on) as the bath was supported on the frame and at the base i felt this was a good alternative.then i packed the surrounding area with pink batts before panelling.
(plumbers usually know there stuff) cheers rackrussel

excellent idea, Rackrussel? Thanks.
Think I'll either use battens across the wall, to bring the gib out, or use a double gib layer. That should give the same effective inset as a 25 mm cut out of the studs, and improve the sound proofing.
Cheers
Mumu

Under the dozens of acrylic baths I have installed here in SA I have used 2 upended plastic buckets full of reasonably stiff (dry) mortar (brickys sand) placed equidistant along the bottom of the bath, sort of like sand castles. Bed the bath down into this levelling etc. Each 'castle' spreads to the other forming a base along the entire length of the bath. Just mind it doesnt spread along to the outlet and gunk up the thread. Any excess mortar can be cut back with a trowel before it sets. I always use brickys sand because its more fatty (contains clay) and doesnt slump as much as other sands.

Here in SA we usually have a concrete slab under the bath. The side and end of the bath are let into the walls so the finished wall (tiles etc) covers the raised lip on the bath for water proofing. This is normally sealed with coloured acrylic sealant as a last thing by the tiler. If one end is shy of the wall build a hob out and down to the bath.

Frame around the skirt of the bath as the others have described or alternatively use hebel block as the norm here.
Jack

I just installed one last month. Wrapped up the waste with a pink batt, boxed in the bottom of the frame and put in 9 20kg bags of washed sand mixed with 2 2bags of cement.....in a reasonably sloppy mix.

The end result it the bath has the feel of a cast iron one.

I glued the bath lip to the frame with Zero Nails, being careful to not get any where the tiles/water proofing went.

The manufacturer suggested all that was needed is timber battens glued to the bottom of the bath. It did not seem enough for me, thus the cement/sand mix.

best of luck

You should also fill the bath before siliconing the edge to the tiles etc. The water will cause the bath to shift a bit and this will stretch the silicon and weaken it over time.

Trav

Bump!

I have a Decina square spa bath with feet, there's probably about 12 or so underneath, and the bath is 1400mm square. It's been installed in a frame on yellow tongue. No tiles around as yet, just cement sheet, and the carpenter put packers around to space for tile.

Question is, with the feet, so I still need to mortar around it somehow? Or should it be fine?
Also, I'd be worried about wet mortar on the yellow tongue anyway... the expanding foam idea sounded good!

Originally Posted by encino_

Bump!

I have a Decina square spa bath with feet, there's probably about 12 or so underneath, and the bath is 1400mm square. It's been installed in a frame on yellow tongue. No tiles around as yet, just cement sheet, and the carpenter put packers around to space for tile.

Question is, with the feet, so I still need to mortar around it somehow? Or should it be fine?
Also, I'd be worried about wet mortar on the yellow tongue anyway... the expanding foam idea sounded good!

Check with the manufacturer, the feet are likely to be designed to be the sole load-bearers.
Although the foam sounds like an attractive idea, it voids many manufacturers warranties.

Cheers
Michael

Wife talked me into getting a proper licensed plumber to install the bath in our ensuite that we were building. Got home from work just in time to see the plumber pocketing the cash my wife had paid him and pick up the last of his tools ready to go. As I stood looking at the bath which was supported by half a tomato stake that he had found in the back yard I said "There's nothing to attach the tiles to". "That's the tilers job mate, not mine" was the reply". I counted to 10 then thought to myself LIVE AND LEARN. Pity this forum hadn't been around then.