James Hardie Philippines, Inc. › Accessories


Question 1

What is the recommended size and grade of steel for HardieFlex fiber cement board?


Recommended grade of steel is Grade 60
Depending on the application: minimum flange width of 35mm

for ceilings, use 0.55BMT - 0.75BMT
for partitions, use 0.75BMT - 1.6BMT

Question 2

How many fasteners do I need for one sheet of HardieFlex?


ApplicationsSize(in mm)Screws on Metal Frame
Nails on Timber Frame
HardieFlex ceilings
1219 x 2438
HardieFlex walls1219 x 24385151
HardieFlex wet area walls1219 x 24386161
HardieFlex senepa254 or 305 x 24381111
HardiePlank siding208 x 36561010
HardiePlank Flooring600 x 240036NA

Question 3

What is the recommended size and grade of steel for HardieFlex® fiber cement board?


We recommend to use a minimum of 0.55mm base metal thickness (BMT), and observe proper spacing of metal frame based on the thickness of the board.

Question 4

Can I use gypsum putty, epoxy or skim coat putty for flush jointing HardieFlex® sheets


No, only HardieStop Base Coat or HardieFlex®Putty Jointing Compound can only be used for flush jointing of HardieFlex sheets. These were specially formulated by James Hardie R & D to work in conjunction with James Hardie building products to provide a seamless finish.

Question 5

Can I use gauze tape in the flush jointing of HardieFlex® sheets


No, it is not recommended to use gauze tape for flush jointing. Use the recommended HardieFlex® Perforated Paper Tape. This was designed to be used in conjunction with the HardieStop Base Coat or HardieFlex Putty Jointing Compound to achieve the best results.

Question 6

What are the specifications of a nail recommended for installing HardieFlex® fiber cement board?


Nails must be protected against corrosion and zinc-coated or galvanized with a head diameter not smaller than 6mm, shaft length of 32mm, and shaft diameter of 2.3mm.

Question 7

Can I use gypsum or the black screws to fasten HardieFlex® sheets to light gauge steel frames?


No, never use gypsum or black screws. Only use HardieDrive Screws. HardieDrive Screws are self-drilling and are fully threaded to firmly secure HardieFlex® sheets to light gauge steel frames.

Question 8

What screw sizes are appropriate for each thickness of HardieFlex sheet?


HardieFlex Screw SizeHardieFlex Sheet thickness
HardieDriveScrew 20mm longHardieFlex 3.5mm & 4.5mm
HardieDriveScrew 25mm longHardieFlex 6.0mm & 9.0mm
HardieDriveScrew 32mm longHardieFlex 12mm
HardieDriveScrew 32mm long wing-tippedHardieFlex Flooring 16.0mm
HardieDriveScrew 38mm long wing-tippedHardieFlexsiding
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Question 9

What is the recommended size of screw for HardiePlank siding?


You must use the HardieDrive Screw 38mm long wing-tippedwith a recommended light gauge steel stud thickness of 0.8mm to 1.6mm BMT . It is specially developed for HardiePlank siding.

Question 10

What is the effective coverage of HardieStop Base Coat and the perforated paper tape?


One kilogram of HardieStop Base Coat has an approximate coverage of 3.7 linear meters while one roll of perforated paper tape can cover at the most 20 HardieFlex sheets

Question 11

What are the types of paints that can be used for HardieFlex fiber cement boards?


The most economical type of paint recommended for HardieFlex fiber cement boards are water-based (latex) paints. Acrylic, vinyl, and PVA are all water-based paints as well. Acrylic can be used for both external and internal applications. Vinyl and PVA are for internal applications. Oil-based (alkyds or enamel) paints can also be used on HardieFlex fiber cement boards, although they would cost more than water-based. These types of paint also need undercoats because these paints soak in too far.

Question 12

Do I need to prime HardieFlex sheets before I apply paint?


As long as you use the recommended water-based paints, you can directly apply paint to HardieFlex sheets after all the joints and fasteners have been covered.