First time laying Hardie on Saturday

[mache]

Hi Guy's,
Saturday will be my first time laying Hardie boards. Hardie 250 boards are going down onto an 18mm ply, level and deflection free floor (level to within 1/8" across any span). I gather the recommended method is SPF with 6mm notched trowel. This part is going to sound like a silly question but here we go. Hardie will be fixed with turbogold screws, but when do you put these in ? I assume that you lay the boards to the SPF base and let that go off when the boards are bedded and leveled and come back a little later to put the screwes through to secure it all down to avoid the screws diggingon side of the board deeper into the bed than the other. Please confirm.

Also whats your method to ensure they are bedded down. Position, wiggle and check with large level, lay next board and do the same ensuring level with the first board down. Drop it down, couple of taps with a hide mallet ??

Sorry if it sounds silly and basic but want to check i'm using the right methodology.

Thanks
Martin.

 

[Dougs Third Go]

screws go in before adhesive has set mache so it pulls the board down into adhesive. I trowel area, drop the board into it, wiggle it, give it a slap with straight edge at various points then screw, you'll need about 50 screws per board

 

[Ian]

http://www.tilersforums.com/43-tiling-forum/58805-installation-hardiebacker-250-500-a.html

 

[mache]

Doug / Bri,

Thanks for the quick replies and advice. Another quick couple of questions if you don't mind.
I'm guessing you don't need to back butter hardie boards, just comb the floor.
Bri you also say in your well laid out thread, to SBR the floor. was this because it was chipboard or do you
do this in every case. I have marine grade ply as the substrate.
On top of the hardie I will be laying the Impey waterguard membrane. In this case would you still tape and scrim the joints or would you fill using a high quality Silicon or gap filling polyurethane adhesive.
Thanks for the support from the forum.
Martin.

 

[Mr Tiler]

if you want my advise mate don't use impey lol where im working it is costing thousands to replace impey systems after just 12 months of usage

 

[White Room]

From my understanding Silicon should'nt have contact with the black stuff...

 

[Mr Tiler]

From my understanding Silicon should'nt have contact with the black stuff...

god forbid if it does mate not even that there trays bounce like a trampoline. even sealing can be a problem

 

[Ian]

Doug / Bri,

Thanks for the quick replies and advice. Another quick couple of questions if you don't mind.
I'm guessing you don't need to back butter hardie boards, just comb the floor.
Bri you also say in your well laid out thread, to SBR the floor. was this because it was chipboard or do you
do this in every case. I have marine grade ply as the substrate.
On top of the hardie I will be laying the Impey waterguard membrane. In this case would you still tape and scrim the joints or would you fill using a high quality Silicon or gap filling polyurethane adhesive.
Thanks for the support from the forum.
Martin.

If you're going to lay a membrane, you don't really need the hardie. Hardie backer is just a suitable surface to tile to, if you're going to impey over it, that becomes null and void, unless you're using it to gain extra height.

 

[White Room]

god forbid if it does mate not even that there trays bounce like a trampoline. even sealing can be a problem

That depends on the kind of installation that was done, a year is pretty poor.

 

[Mr Tiler]

That depends on the kind of installation that was done, a year is pretty poor.

its the system itself mate, a floor that has been strengthened twice under the tray and tiles still crack means theres too much play in the tray itself. and its half a site at over 3,000 a time

 

[prceramics]

if the floor is flat you can get away with a 4mm notched trowel, why use more addy than needed

 

[mache]

Bri,
Not using for height but I am fitting Electric UFH, by using hardie this should allow me to use a 150W element cable rather than 100w normally recommended for direct to wood substrate. Also give me a bit extra thickness to bed the floor temperature sensor into.

Whitebeam, Waterguard is the newer membrane from Impey rather than the older bitumen based tile safe product that I think youm did have to be careful which products came into cantact with although I think it was more expoy products that had the issue.

Mr Teabag, Interesting comment, upto now I've not seen particulary bad comments on the impey systems. Do you know which versions of the membranes, formers were used in the installs you are working on, I thought the aqua decks were one of the most rigid out there(subject to correct installation)

 

[mache]

if the floor is flat you can get away with a 4mm notched trowel, why use more addy than needed

4mm it will be then, appreciate all the inputs

 

[One Day]

Impey "anything" is more hassle than it's worth in my experience.
Pretty much all the failed wet floors I've attended have involved either their trays or membranes.
That's partly down to the sales channels - builders and plumbers as well as sheer volume of sales but there are plenty of ways to muck up the installation of Impey gear.
Other systems are much safer (poss' easier?) to install in that there is either a right way or a wrong way.
Too many in-betweens and vague areas with Impey I'm afraid.

 

[Mr Tiler]

Whitebeam, Waterguard is the newer membrane from Impey rather than the older bitumen based tile safe product that I think youm did have to be careful which products came into cantact with although I think it was more expoy products that had the issue.

Mr Teabag, Interesting comment, upto now I've not seen particulary bad comments on the impey systems. Do you know which versions of the membranes, formers were used in the installs you are working on, I thought the aqua decks were one of the most rigid out there(subject to correct installation)

hi bud, I wouldn't of commented without knowledge. I will deffinately try to find out what system has been used. all i know is an impey system has been used throughout all of the building sites i currently am working on and it has not gone well, 12 months down the line they are all failing and it is not down to installation. and very recently a wetroom repair that had previously been repaired they tried to strengthen underneath the tray for a second time and once my big backside stood on top was bouncing (i could even see it moving let alone the guy with his eye against the ground)... its costing thousands per property as it is all mosaic stone too!