Bizarre rendering job... - How would you approach this one????

[Ted]

An architect has come to me and asked me if I can do a job for her. She explained the job and asked me to go away and come back with a price. I went away and thought about it and came back to her and said I wasn't prepared to the job as I didn't think the building method was great. She has told me that I can work on a day rate and if it doesn't work, it doesn't work.

Basically, she wants me to focus on one bathroomn wall. This wall is a perfectly normal masonry wall with a window in the middle of it. Below the window she want me to build a vanity unit out of lightweight concrete blocks (ie, Thermalites). She wants me to saw them up so the vanity unit is a random shape rather than a boxy shape. She then wants me to render the vanity unit and the wall so it is all one flowing thing IYSWIM.

Obviously there are some complications such as taps and waste but these are not my greatest concern. My concern is getting the thing water tight. I was actually planning on using concrete on the horizontal part of the vanity unit. She wants me to sculpt out a random shaped sink and I propose to make the concrete fairly strong around the sink (4" thick) and then blend the render in to the concrete up over the side of the the thermalites and into the countertop.

A number of builders have told me this whole idea won't work. It is certainly not how I would do it. I would precast a sink and countertop and work out a way of blending them relatively seamlessly into the render.

What doi you anticipate being the biggest problems on this job?

One guy told me to build the structure out of wood rather than thermalites. I think this is a good idea but I am not a hot shit chippy and laying blocks is pretty easy...

Another guy told me to mix lime in with the render/concrete to prevent the thermalites from cracking..

How would you do this job or would you run a mile? I am going to do it as I know the lady well and she is paying me at the end of each day. If it works to her satiisfaction, then it works. If it doesn't then it is her problem...!!!

[glyn1206]

I wouldn't touch the job with a barge pole!
She may be paying you , but if it doesn't come out as she imagines it will.it's your reputation on the line.As you know it takes years to build up a good reputation,but one bad job and its all down the pan!

[Ted]

I work all over the place so even if she decided to bad mouth me if it went wrong (which I think is highly unlikely; her bad mouthing me; I think it is almost only a 50% chance the thing will work OK) it wouldn't affect me that much.

And I have put it in writing that I disprove of this building method, but if she wants to hire me to build a unit and render it despite my written reservations, she is welcome to. I have worked for her before and I really don't anticipate any problems. She is an architect and likes trying things out. I think her expectations are far lower than what I am trying to achieve too.

[lutonlagerlout]

i have done stuff for 3 architects at their homes ted and its never straightforward
i dont think thermalites will work,maybe agilites or fibolites
is she gonna tile it with mosaic tiles? myabe you need to waterproof it before the render goes on with 3 coats of bitumen
it sounds nuts ,but go for it
god loves a trier
can you do us a b4 and after picture ted?
cheers LLL

[Ted]

This is work for her in her home, not for a client thankfully.

She wants a rough textured finish and says a trowlled finish is fine, even for the countertop!

I have suggested that she may well want me to polish it.

I wanted to precast a concrete sink and insert a glass sink inside this. But she didn't like this idea. Concrete sinks are prone to stains so are not that great in high wear and tear places (dreadful kitchen sinks but people like 'em) and they do erode down after a few years of use. Glass and stainless steel are much better sink materials.

Cheers for the suggestions. I will defo try and sort out some pics. Just need to work out how to post them after that...

Bitumen iis a good idea.

Why do you think the blocks you mention are better exactly?

[TarmacLady]

what about a stainless sink? Not what I'd want in my bath, but could be made to match the contours, and would be fairly stain free, waterproof, and would be that sort of cold colour and organic shape it sounds like she wants. It could even be bashed into place to look even rougher.

(I'll take the traditional sinks and vanities, ta.)

[mouldmaker]

One option - not sure it's the best - would be to have the whole unit cast in one piece off-site in glass reinforced concrete. We've done stuff like that before.

[Ted]

One option - not sure it's the best - would be to have the whole unit cast in one piece off-site in glass reinforced concrete. We've done stuff like that before.

I wanted to pre-cast but she doesn't.

Pre-cast is the way to go IMO.

[Ted]

what about a stainless sink? Not what I'd want in my bath, but could be made to match the contours, and would be fairly stain free, waterproof, and would be that sort of cold colour and organic shape it sounds like she wants. It could even be bashed into place to look even rougher.

(I'll take the traditional sinks and vanities, ta.)

She wants the sink, vanity unit and wall to all be one flowing thing. So the wall, vanity unit and sink all have to be covered in the same material.

She actually wants it to be white render. I was proposing to use a 6:1:1 mix (ie, 6 Dolomite (mix of grades): 1 Snowcrete: 1 Lime). The lime should stop the concrete/render from shattering the thermalites is my thinking...

She won't even let me inset a glass sink so you can see the white concrete beneath. Not her vision apparently!

[lutonlagerlout]

the reason for fibolites or agilites is that they are less prone to cracking when rendered
thermalites are a pin in the neck
tbh ted they all have these half baked ideas
one bloke wanted all his downstairs walls changed to glass blocks: till he got the quote
she sounds right off her rocker,be careful
regards LLL

[Ted]

the reason for fibolites or agilites is that they are less prone to cracking when rendered
thermalites are a pin in the neck
tbh ted they all have these half baked ideas
one bloke wanted all his downstairs walls changed to glass blocks: till he got the quote
she sounds right off her rocker,be careful
regards LLL

I whacked fibolites and agilites in google but did not come up with much.

Can I get them in a normal BM such as Buildbase or the dreaded TP or Jewsons? Or do they normally have to be ordered in all but the biggest BMs?

e2a: I have found fibolites, cheers.

She is off her rocker but she is OK. She is a "crusty" architect (a hippy basically). I don't think she trained in this country but she has got me some interesting jobs before but this one is a bit mad IMO. I could have pre-cast her something beyond her imagination.

[simeonronacrete]

If you decide to go ahead, and if render is the finish needed, then using a cement:sharp sand mortar with Ronafix and water will give you a watertight render - if it's good enough in a swimming pool it's good enough for a bathroom sink.

The mix for the bonding primer is:
1:1 Ronafix : cement

The mix for the render is:
1:2.5 cement : dry medium sharp sand
Gauged with 3:1 Ronafix : water

Mix by adding enough of the Ronafix / water solution to the cement and sand to give a render consistency.

Apply 1 x 6mm coat to the damped and primed surface, comb it and let it cure for 6-12 hours at 20oC.

Prime again and apply second 6mm coat.

Leave with wood float or steel trowelled finish.

Cure and protect for 24 hours.

Et voila - watertight render!

See our web site
www.ronacrete.co.uk
Products
Waterproofing
Documents
Ronafix Render, admixture, w/proof, w/tight, BBA, 10yr ins

Good luck!

[TarmacLady]

I think McGyver was sorely lacking - he didn't have a tin of any Ronacrete product in his leather jacket :p

[mouldmaker]

I think McGyver was sorely lacking - he didn't have a tin of any Ronacrete product in his leather jacket :p

Only because Simeon didn't know his email address...

[Ted]

Simeon, cheers for the reply...

I have made a mock vanity unit and it seems to work; the render looks very nice but it is not the style I would have in my bathroom.

I used Sika waterproofer in the mock. What advantages does Ronafix offer offer over Sika? Also what colour is your waterproofer? Sika is white which is good for my white render... if a waterproofer is not white it may well affect the final colour of the piece...

Where do I but Ronafix stuff? Do I order it in Buildbase or TP or from you direct?