For homeowners just starting their research into James Hardie fiber cement siding, sometimes it seems like there are more questions than answers! This is especially true for people who are thinking of installing their own siding.
We’ve been exhibitors at dozens of home and garden shows, so we’ve been asked all kinds of questions by DIYers who want to tackle their own project. Here are some of the most common ones!
what is the best saw blade for James hardie siding?
For a larger project, use a fiber cement saw blade with polycrystalline diamond tips; if you’re installing Hardie siding on a shed or other small building you can use a fiber cement saw blade with carbide tips. For installations with more or longer cuts, the carbide blade will burn out much more quickly.
Some good brands of fiber cement saw blades include: Norske, Diablo, Freud, Milwaukee, and Hitachi. Any of these will work well.
(Pro tip: don’t bother with the 12” blade. Because HardieBlades are thinner to reduce dust, the 12” blades tend to wobble quite a bit. Most 12” miter saws will take a 10” blade, which is quite a bit more stable.)
You can always spot a fiber cement saw blade by looking for the blade with an unusually low number of teeth. A 7.25” blade should have four teeth, a 10” blade should have six teeth, and a 12” blade should have eight teeth.
Can you use a wood or concrete blade to cut James Hardie siding?
You shouldn’t use a wood blade to cut Hardie or other fiber cement siding. The higher teeth-per-inch count creates more fine dust particles. This increases the installer’s exposure to respirable silica dust, which can lead to future health problems.
A continuous rim concrete blade is even worse: you are essentially grinding the Hardie into a fine powder, which is the last thing you want to do for your health.
Do I need to wear a respirator or mask to cut fiber cement siding?
Not usually, as long as you are cutting outdoors in a well ventilated area and are using the right tools. Check to make sure that you are following the manufacturer’s guidelines for cutting.
What are the best nails to use for James Hardie siding?
For a normal installation, we use 2” long stainless-steel ring shank coil nails for a pneumatic siding gun. If you can’t find stainless-steel siding nails, hot-dip galvanized nails meet Hardie’s minimum requirements. Electro-galvanized nails are not recommended.
Can you install Hardie Siding with roofing nails?
Yes you can! James Hardie has tested their siding with both siding nails and roofing nails.
Can you hand nail Hardie Board?
You definitely can, but it might not be the best idea. If you are installing more than a few boards, it’s a good idea to buy or rent a compressor and a nail-gun.
Can you install Hardie siding with screws?
Yes you can install Hardie with screws if you like! For HardiePlank lap siding, use a #8 wafer head wood screw with a drill point. If you can’t find one with a drill point, you can pre-drill the siding instead.
How do you install Hardie siding by yourself?
If you are planning to install Hardie board without a helper, make sure you buy a set of siding gauges, such as the Gecko Gauge by Pac Tool. The Gecko Gauge clamps to the board you just installed, and holds up the next board while you nail it. Almost all professional Hardie installers use this tool.
The Gecko Gauge is extremely useful for installing fiber cement siding by yourself
Can you install Hardie Siding over rigid insulation boards?
Yes, you can install Hardie siding directly over rigid insulation and other non-nailable materials up to 1” thick. For thicker insulation, you will need to install wood or metal furring.
What type of caulking should I use with Hardie siding?
The best caulking to use is Quad or QuadMAX caulking, manufactured by Lepage (in Canada) or OSI (in the USA). There are a bunch of caulking products that meet James Hardie’s requirements for durability and flexibility, but Quad and QuadMAX caulking have the best matches to James Hardie’s ColorPlus colours. Always remember to match the caulking to the colour of the siding, not the trim.
How heavy is Hardie Board?
HardiePlank siding itself weighs 2.5 pounds per square foot when installed. If you factor in the corner and window trims, the whole wall assembly will usually come in somewhere around 3 to 3.5 pounds per square foot.
What is the best house wrap to use with Hardie siding?
James Hardie siding is compatible with any water resistive barrier that meets U.S. building code requirements. You can use Tyvek, Typar, HardieWrap, TamlynWrap, or plain old tar paper if you really want to.
Do you have to use HardieWrap weather barrier with HardiePlank?
No HardieWrap is not required: you can use any code-compliant house wrap.
Does hardie Board contain asbestos?
No it doesn’t: not since the 1980s when James Hardie started using cellulose fibers instead of asbestos in the formula. These days, asbestos in Hardie is just a myth that other siding sales reps are happy to repeat to try to sell their own products, but it’s simply not true.
How do you mount a mailbox onto Hardie siding?
Make sure that your mounting screws bite into the wood sheathing or studs beneath the siding: the HardiePlank material itself won’t hold the screw threads for long.
How often should Hardie Board siding be painted?
If you install James Hardie’s ColorPlus pre-painted siding, you shouldn’t have to worry about re-painting for at least 15 years: that’s how long the Hardie finish warranty lasts. After you re-paint Hardie, a high quality paint job should last you between 8 to 12 years depending on your climate.
What is the R-Value of Hardie Board?
Like most siding products, James Hardie siding has almost no R-value on its own.
Is Hardie Siding brittle?
It’s not nearly as brittle as some people would have you believe. One person can easily move HardiePlank and HardieTrim without damaging it.