FAQS

Application / Installation


1.) What are the different James Hardie building products and its recommended applications?

  • HardieFlex® ceilings can be easily installed in the living room, bedroom, bathroom, attic, loft, basement, corridor, kitchen, and garage ceilings where a more quality stringent finish is required.
  • HardieFlex® walls can be used for vertical partitions and for bedroom, living room, corridor, and dining area walls.
  • HardieFlex® wet area walls can be used for bathrooms, restrooms, kitchens, interior gardens, washing and laundry areas.
  • HardiePlank® siding adds protection and design value to a home. It can be used both externally and internally as design accent to a home.
  • HardiePlank® Flooringis a substrate for internal residential applications. It is ready to accept various floor finishes.
 

2.) Can we install HardieFlex® ceilings, walls and wet area walls with the same nailing pattern as plywood?

No. HardieFlex® ceilings, walls and wet area walls should be installed with nails 50mm from the corner to avoid break-outs on the corners. Nails must be 12mm from the edge and 200mm (8") on centers across the body of the sheet and along supporting edges.
 

3.) Is it alright to cut HardieFlex® fiber cement boards with a handsaw?

No. Use HardieFlex® scoring knife for cutting HardieFlex® fiber cement boards. A handsaw will become blunt after cutting through any James Hardie building product. Other alternatives would be to use a circular saw with a HardieBlade® saw blade or a hand guillotine. If you are cutting outdoors, position your cutting station in such a way that the wind will blow dust away from you. It is also advisable to use a dust-reducing circular saw connected to a vacuum with HEPA filter, and wear an N95 dust mask when sanding, rebating, drilling, or other machining works.
 

4.) Can I use HardieFlex® ceilings on internal wall applications?

Yes. HardieFlex® sheets with a minimum thickness of 4.5mm can be used for internal walls in residential applications. It can also be used for other applications such as ceilings and eaves. We do not recommend HardieFlex® 3.5mm for internal walls applications. However, for high traffic areas, such as commercial establishments, minimum sheet thickness of 6.0mm is recommended for extra impact resistance.
 

5.) What is the minimum thickness of light gauge steel studs required to install HardieFlex®fiber cement boards?

For most HardieFlex boards, the recommended light gauge steel stud thickness is 0.55mm BMT (Base Metal Thickness) or 0.60mm Nominal Finished Thickness. The maximum recommended thickness is 1.60mm BMT.

For HardiePlank siding, the recommended light gauge steel stud thickness is 0.8mm BMT.

For HardieFlex® Flooring, the minimum steel stud thickness should be 1.2mm BMT.

 

6.) What is the recommended size of timber frame for HardieFlex® fiber cement board (6mm thick)?

For partition, use a 2' x 3' kiln-dried softwood timber with a minimum stud width of 35mm. For ceilings, use a 2' x 2' kiln-dried softwood timber with a minimum stud width of 35mm
 

7.) What kind of HardieFlex® fiber cement board should be used if tiles are to be applied to it?

A minimum thickness of 6.0mm HardieFlex® sheet must be used, you can also use HardieFlex® 9.0mm and 12.0mm depending on the size and weight of the tiles intended to be installed.

HardieFlex® Wet Area Walls (mm) Maximum Tile Thickness (mm)
6 13
9 18
12 >25*
*Support angles are recommended
 

8.) Can I install HardieFlex® 3.5mm on timber and steel frames?

Yes, HardieFlex® 3.5mm can be fixed to both timber and steel frames.
 

9.) Can we use HardieFlex® fiber cement boards as underlay for roof shingles?

We do not recommend HardieFlex® sheets for such applications.
 

10.) Can we install HardiePlank® cladding direct to masonry?

Yes, HardiePlank® cladding may be installed directly to masonry using a pointed screw 8 x 38mm in conjunction with a plastic anchor.
 

11.) Can we use HardieFlex® fiber cement boards for structures near the shore?

Yes, HardieFlex® fiber cement boards can be used for structures near the seashore. However, damp, shady situations, agriculture, or sea spray environments may induce an extra tendency for mold growth. Use mold inhibiting and alkaline resistant undercoats and always consult the paint manufacturer for maximum mold resistant paints. Ensure that the fasteners (nails and screws) have the required level of durability for the local environment.
 

12.) Can HardieFlex® fiber cement boards be used for curved walls?

Yes, here are some recommendations for such applications:

  • The minimum bending radius for HardieFlex® ceilings and walls is 1.2m along the length and 1.8m along the width.
  • The minimum bending radius for HardieFlex® wet area walls is 1.8m along the length and 2.4m along the width.
  • To maintain the smoothness of the curved wall, studs are required at maximum spacings as shown below:
 
Range of Radii (mm) Stud spacing (mm)
1200 150
1201 - 1800 200
1801 - 3000 300
3001 - 20000 450
Above 20000 600
 

13.) Can HardieFlex® fiber cement boards be used for flooring?

Yes, you can use HardieFlex® Flooring 16.0mm as a flooring substrate for internal residential applications. You can directly apply floor finishes onto HardieFlex® Flooring such as tiles, vinyl, wood laminates, linoleum and carpet.
 

14.) Can we use HardieFlex® sheets as linings for ovens?

No, you cannot use HardieFlex® sheets as linings for ovens. Although HardieFlex® sheets can be subjected to high temperature, frequent and/or regular exposure to such temperatures will eventually damage the boards.
 

15.) Can HardieFlex® Flooring be used as an external application; e.g. deck, terrace, patio, etc.?

HardieFlex® Flooring can only be used as an internal application for homes such as lofts, second floors, attics, mezzanines, and toilet and bath area
 

16.) Is HardieFlex® Flooring applicable to toilet and bath areas?

Yes, but a third party waterproofing system must be applied in the whole area.
Refer to the third party waterproofing system manufacturer on their warranty, suitability and installation instructions.
 

17.) Is it okay to use HardieFlex® Flooring for stairs and stairs landing?

Yes, as long as the four sides are fully supported and its width of support will not be more than 300mm. It must also be covered with a floor finish.
 

18.) It is okay to use HardieFlex® Flooring as the finished flooring?

No, HardieFlex® Flooring is meant to be a flooring substrate for internal residential applications. Using it as the finished flooring will scratch the coating of the board and damage the board itself, so a floor finish such as tiles, vinyl, wood laminates, or carpet must be laid over it.