We've used Swanstone and Onyx in two different showers and were hapy with both. What sort of advice are you looking for?

I investigated this option recently - see thread below. I also ran into code difficulties before we'd even started as my preferred choices were from European & custom manufacturers.

Here is a link that might be useful: some discussion on solid surfaces

I'd order the pan and frame the shower to hold it. Otherwise you risk needing a custom, and thus much more expensive, pan. Installation isn't much more than cutting the drain hole in the subfloor and shoving the pan into place. Any contractor should be able to do it.

We had solid surface shower walls in our last bathroom and they were very easy to clean with standard cleaning products.

Never tried slab granite.

astaw and weedyacres....Is the onyx collection acrylic?

astaw did you find a 48 x 60 base from someone as one of their standard sizes or did you (or will you) have to order it custom?

I'm having a hard time finding a base that is standard in this larger size...

Thanks.

Here's what Onyx pans are made of (from website):

Here is a little information on our chemistry:

63% of our products is a hydrate crystal--Al2O3+3H2O. Alumina is also the main ingredient in Corian© and all "solid surface" products. The main ingredient in our product (alumina trihydrate) is in roofing materials and the plastics inside automobiles to slow flame spread and as a smoke retardant. It is in the plastic coating on the wiring in your home (in a much smaller percentage).

Our other 37% is a special polyester resin we developed over the last 22 years (and continue to improve) to get the properties which allow us to say "Yes, Guaranteed Forever".

We all try to get properties which make our products work best for our applications. Our application is the bathroom. We believe our resin serves this purpose well. Corian© uses acrylic resin, others use various blends of polyesters or modified acrylics. We prefer our resin for our products and it serves us well.

We use cultured marble type molds to cast our products. The solid surface industry casts sheet goods and fabricates their products. The cultured marble industry uses calcium carbonate as their main ingredient.

Our Gloss finish does have a gelcoat on the surface (about 15 mils) similar to cultured marble. Our Gelcoat is ISO-NPG.

ISO-NPG gelcoat is a tight molecule--very resistant to water penetration. Our Matte finish does not have gelcoat on the surface. We use a different blend of resin for Matte.

Our products are real hybrids. The resin in the matte finish--we substitute 30% of the normal ortho resin with ISO-NPG resin. This increases the ability of the product to resist moisture penetration. This is necessary without the ISO-NPG gelcoat coat which is on our gloss products.

And here's the link to Onyx's standard sizes.

Here is a link that might be useful: Onyx shower bases

I have ordered the onyx shower base. The 48' x60" required a custom order. The top width of the base is 3/8" so that put the 2cm granite slab out of the picture. I am considering using a solid color non-glazed rectified porcelain tile for the shower walls. Any advice? Also, a special thank you to weedyacres for the tech information on the onyx. I noticed that you also used radiant floor heating satisfactorily. May I ask what was brand that you used? Thanks

Radiant heat was from Warming Systems. It's cheaper than the mats, but takes longer to install. There are a couple recent threads on heated floors with more info.

I had a custom pan poured for our 5X4 shower pan it is made out of cultured granite & looks very nice. I just didn't want to deal with the grout down there.

Is it possible to just put a solid bottom and then tile the sides? I just want a solid bottom that has a bit of a lip on it. I don't want to have to replace all the tile or put in solid sides, when the tile is perfectly fine.

@coco you can just put the corian shower base down and tile up the side - Formed has pictures of what you after, I've linked their shower screens but you can see they have a corian shower base used in the photo.

Here is a link that might be useful: Formed Shower Screen with Corian base