Installation of Masonite/HDF flooring

[erinb]

We are doing renovations on our stage in a short amount of time, including installing new flooring. I have 21 sheets of HDF/Masonite to install and a great team to help, but unfortunately not a lot of experience with it. I have a few questions and any information is great appreciated! Thanks in advance!

1. Do the boards HAVE to be prepainted or can they be done after everything is down?
2. I read on a thread that it is recommended to prime/paint BOTH sides. Is this necessary and why?
3. Can the full 4x8 sheet be installed or should it be ripped to a smaller size?
4. Any specific screw configuration recommended (ie just along edges or throughout board)?
5. A common recommendation was to leave a small gap when installing. One suggestion said to cover the gaps with Gaff Tape. Has anyone done this? Does the tape show through the paint?

 

[Footer]

Every single one of those suggestions is done to prevent the floor from bubbling when humidity changes. Priming both sides seals the masonite. Leaving that gap gives the sheet good somewhere to expand. I don't suggest you gaff the seams, masking tape does work rather well though.

 

[derekleffew]

From a post on the Stagecraft Mailing List:

Our sacrificial 1/4" tempered Masonite deck was coated BOTH sides with alkyd
based primer, spaced with dimes, and then nailed down with 1.25" ring-shank
nails spaced 8" on the edges and 12" in the field.

This is the same advice I gave to a local [upstate NY] high school when they were
pondering a deck for their new facility. Nearly every suggestion was ignored
by the contractors who put down a 3/16" untempered sheet with screws after
priming only the top. Then they turn off the HVAC to save $$ over the
summer. They are in the process of replacing the whole floor as I type.

 

[erinb]

Any advice if only one side of the board is tempered?

 

[josh88]

well you run into problems because you only have one side of it sealed, so there is still potential for moisture to get down to the unsealed side and wreak havoc on it. Untreated fiberboards do not like moisture, or rather do not interact well with it.

 

[Chris15]

Untreated fiberboards do not like moisture, or rather do not interact well with it.

I'd actually argue that they LOVE moisture, they suck it up like there is no tomorrow...

 

[kicknargel]

And ideally, you'd want to prime all six sides of the sheet (including the edges) to seal against moisture.