waterproofing membrane -which one?

[joe bloggs]

Does anybody have a recommendation for a particular brand of waterproofing membrane? The bathroom I'm redoing has an 18mm compressed fibre floor over t&g flooring. The house is pole home and tends to have a bit more movment than is normal. I'm thinking about using Davco Dampflex reo, is there a membrane that might be more suited to this application?

[journeyman Mick]

Joe,
all membrane materials have to meet Australian Standards so in theory they're all fine. There are two sorts though,
1) membrane and reinforcement in one pot, has fibreglass mixed into it.
2) seperate fibreglass reinforcement is placed and the membrane material painted on.
type 1 is easier to use, type 2 is usually used in commercial applications.

Mick

[bitingmidge]

One of the big advantages with type 2 is that you can guarantee the thickness of the coating.

Unless the liquid membrane is applied with the minimum thickness required by the manufacturer, it is doomed! By applying it over/through fibreglass, you can be sure that you have it at least the thickness of the reinforcing.

Cheers,

P

[Theva]

Joe Bloggs,

If it is an existing bathroom then epoxy based products with fibreglass reinforcement applied by a processional is a better option. If the surfaces are new and you want to do it in DIY mode then the product is ok.

The same product was used in our bathroom over compressed sheets. Sheets were butt jointed with epoxy as per recommendations. All screws, joints, wall / floor joints were topped with silicone.

All corners & joints were treated with a first coat and polyester reinforcement; then three coats of membrane all over, including walls up to shower hight. Be prepared for only half of the recommended coverage per lit.

Regards,

Theva