Joint flashing: James Hardie recommends that a slip sheet (joint flashing) is installed behind each butt joint in the siding. This is a 6” wide piece of weather resistive material to make sure that no water gets through.

Does Hardie siding require OSB?

GENERAL REQUIREMENTS: HardiePlank® lap siding can be installed over braced wood or steel studs spaced a maximum of 24" o.c. or directly to minimum 7/16" thick OSB sheathing.

Do I need sheathing under fiber cement siding?

Fiber cement siding should be installed over plywood, OSB, or sheathing. Be sure that the siding installed is dry. Otherwise, it might shrink at butt joints.

Does Hardie board need a vapor barrier?

Depending on your local building authority having jurisdiction (the AHJ) over your building codes, vapor barriers are almost always required, whether your builder uses James Hardie products or some other, inferior product.

Do I need plastic behind Hardie board?

plastic behind cement board with waterproofing is essentially suspenders when you already have a belt. the waterproofing is also a vapor retarder so if the red guard or kerdi product is continuous, lapping corners and all, the plastic will be unnecessary.

How Its Made - James Hardie Siding

What do you put under Hardieboard?

Either is acceptable, but we recommend that the smooth side with the nailing pattern of every 8" on center go up. What subfloor should HardieBacker® cement board be installed over? The minimum subfloor specified is 5/8" exterior grade plywood or 23/32'' exterior grade OSB subflooring.

Do you caulk Hardie board siding?

When James Hardie siding products butt into wood-based materials, a 1/8" gap will allow for expansion and contraction of the wood-based product. Caulks and Sealants: James Hardie recommends the use of caulks and sealants that remain permanently flexible.

What do you put between siding and ground?

Fiber cement should be kept at least 6 inches above the ground. It's recommended to keep the bottom edge of the first course even with the bottom edge of the trim. The most popular brand of fiber cement is James Hardie. In fact, the name is practically synonymous with the siding material.

Should there be plywood under siding?

The wood that goes under residential siding – exterior sheathing – performs several functions. It adds insulation, waterproofing and structural support for the framing. It also provides a surface on which to nail the siding. The most common sheathing materials include oriented strand board and plywood.

What do you hang fiber cement siding with?

Fiber cement siding can be nailed by hand or with a pneumatic nailer. It can also be attached using corrosion resistant screws. Use hot-dipped galvanized or stainless steel nails. Nails should penetrate through the sheathing and at least 1” into studs.

Can Hardie board be installed on studs?

HardiePlank® lap siding can be installed over braced wood or steel studs, 20 gauge (33 mils) minimum to 16 gauge (54 mils) maximum, spaced a maximum of 24 in o.c. or directly to minimum 7/16 in thick OSB sheathing.

Can fiber cement siding touch the ground?

Ground Contact: While fiber cement siding is made to shed water, it's not designed to be buried in wet soil. Most manufacturers of fiber cement siding, and many building codes, recommend keeping the siding at least 6” off the ground.

Should you paint the backside of Hardie board siding?

All sides of the Hardie Board are painted (even the edges) and therefore the entire board is completely sealed. (Although Hardie Board comes from the factory without the back of the board primed, according to James Hardie's support department, they say you can prime and paint the entire board.)

Do you leave a gap between Hardie board siding?

Hardie siding requires a minimum 2” gap from all hard surfaces like decks or rooflines, and at least 8” from any soft surfaces like grass, dirt, or gravel.

Should Hardie board have gaps?

Do not caulk fiber cement siding butt joints/edges. It is never acceptable to leave a gap of any size at a butt end/joint. Butt end/joints should be installed with factory sealed or factory-prefinished ends butted together in moderate contact.

Can I use a framing nailer for Hardie siding?

The answer is, yes. Framing nail guns can be used for siding installation, if the nail being used is long enough to attach the siding firmly to your exterior wood sheathing. While it's recommended to always use a siding nail gun for siding installation, in a pinch, you may be able to use a framing nailer instead.

Can you screw into Hardie board siding?

Yes, you can drive screws into the Hardie board if you use suitable screws. Hardie Board requires using specific screws to work effectively. For best results, use ribbed stainless steel screws with wafer-head.

Should I put thinset under cement board?

Not only is thinset a critical component underneath cement board but the other critical component is the fasteners. And you won't have the fasteners if you are trying to install it over concrete.

Do you have to use thinset under Hardie board?

However, many manufacturers including, both Durock and Hardiebacker not only recommend that you use thinset under their backerboard, but they specify it and will void the warranty on their product if it's not used.

Does Hardie board provide insulation?

Hardie Plank is a cement board; it's composition is sand and water. It is heavy on the wall and provides no insulation value.