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Fiber Cement Siding Tips

I'll bet you have seen houses that have fiber cement siding or shingles. The best place to see them is in older parts of your town or city or those sub-divisions built in the 1950's or 1960's. The shingles look like large sized armor plating. The houses that are in the older parts of your town may be up to 100 years old. If you are lucky you may spy one that has never been painted. In these instances the shingles will have a multi-colored look upon close inspection. What a cool product! One that has truly passed the test of time.

Installing Fiber Cement

These products are installed in the same manner as any exterior siding product whether it be wood, vinyl or other siding. It is simply nailed to the exterior walls. My initial reaction when I first came into contact with this material is that it would crack when you nailed it. Not so! The older fiber cement that is 100 years old is brittle, but not the newer products. Sure, you can crack it if you hit it hard enough, but you will be surprised how well nails go through it.

Water Barriers

When I drive by certain new home construction sites I often get cold chills. I am shocked to see carpenters install siding products directly over exterior sheathing with NO water barriers between the exterior siding and the plywood, OSB or foam sheathing. This is a huge mistake in my opinion. Even a superior product like fiber cement siding or shingles can allow water to get past a butt joint or where it touches up against doors, windows or corner boards. Water barriers like traditional tar paper or the newer air and water infiltration barriers are a must. Carpenters from generations ago discovered that tar paper absolutely kept wood sheathing dry. I can vouch for this. Many older homes that I took apart in order to add a room had tar paper under the siding that was brittle but it still stopped water! Make sure that a water barrier is part of your installation. I don't care what the building code or the carpenter says!

Cutting Fiber Cement

This is probably the most difficult part of the job. You can use a regular circular saw with a carbide tipped blade, but you better have a dust mask. This method creates lots of dust. The dust will eventually ruin the bearings in the saw, so use an old saw if you must go this route. You can use an electric shears if you want to avoid dust. The tool is primarily used by professionals as it is fairly expensive. It is definitely not a tool to use for just one weekend. There is a good possibility that a tool rental center might have one if you just need it for several days. Check out the web site of Pacific International Tool & Shear for more information about this tool.


The newer fiber cement panels need to be painted. They don't have the cool built-in color of the 100 year old products. the good news is that these products hold paint exceptionally well. The fiber cement is very dimensionally stable and simply doesn't expand or contract. This means paint will hold on for a very long time. I would paint the product with the new paint I discovered that contains polyurethane. It is Weatherbeater Ultra, sold at Sears. Make sure that the fiber cement siding is nice and clean and dust free before painting.


Always use the best nails when installing fiber cement. If you can find stainless steel nails, use them. If not, go for the hot dipped galvanized nails. Some installers will use nails driven by air nailers. These are galvanized, but most do not perform as well as hot dipped galvanized.

Keep in mind that some fiber cement products can be blind nailed. This is a good thing! Blind nailing is the way most roof shingles are installed. In other words, you don't see the nails. Consider selecting a fiber cement product that can be blind nailed. This will eliminate all sorts of problems you can often have with exposed surface nails. Always read the installation instructions and use the nails that the siding manufacturer says to use.

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