One huge expense that has affected many homeowners and painters over the last 15 years was the replacement of their faulty LP siding. The class action suit against Louisiana Pacific for selling the faulty siding lasted for years. Many homeowners never recovered money from the lawsuit as the money allocated ran out.

During this period of time a new type of siding entered the market that offered the durability that most homeowners demanded. It was perfect timing for a cement based siding to enter the market. Many homeowners and builders rushed to buy hardiePlank to replace the decaying siding that plagued the housing industry. Finally a siding existed that would probably outlast the owner. This siding was view by most folks as being as good as snuff and not half as dusty.

Most painters in our industry welcomed the siding. Not having to deal with swelling siding that wouldn't hold paint, certainly made our job easier. During the advent of this new siding, a different kind of problem emerged for homeowners and painters. The problem was and still is: How do you keep HardiePlank caulked?

For homes that have exposure to sunlight and widely varying temperatures, keeping HardiePlank properly caulked is a challenge. HardiePlank expands and contracts a lot under these conditions. Most caulks simply do not have the elasticity to handle the expansion and contraction.

I have seen the expansion and contraction of HardiePlank siding pull fresh caulk apart within 24 hours after application. It's great siding to have on your home, but you better know what you're doing when it comes to caulking all the joints.

You certainly can't be economy minded with your purchase of caulk when HardiePlank is involved, or you will be doing the job over again. Many painters and homeowners alike seem confused when selecting caulk for this siding. It has been my experience that you should be using caulks that comply with either ASTM C 834 or ASTM C 920. Caulks that fall into this category are in accordance with caulking manufacturers written instructions.

I personally prefer using an elastomeric caulk on my customer's homes. Elastomeric caulks are made for masonry substrate surfaces. Sherwin Williams carries a product called Shermax Super Stretch Elastomeric Caulk that I find works well with HardiePlank Siding. It has the elasticity to handle the constant expanding and contracting of HardiePlank. I require all my crews to use this product for most applications and I see far less problems with caulk separation. One common problem that many homeowners find is the HardiePlank itself was installed improperly. At least a 1/8 inch gap between siding and trim should be left by the installer to allow for a proper amount of caulk to be applied. The 1/8 inch gap is in accordance with caulking manufacturers written instructions. (Leave 1/8'' gap at trim and butt joints for caulk.) If less than 1/8 inch gap is available to apply caulk, then the caulk is too thin to handle the amount of stretching it must endure. I have seen Elastomeric Caulk separate where less than a 1/8 inch of a gap existed in the siding joints. Owens Corning also sells a very good caulk for this type application.

The last point I want to make is there are solutions to this common annoyance. As a painter make sure you are giving your customer the best solution for this problem. As a homeowner make sure you discuss your painter's plans on how he is going to solve this common problem with HardiePlank. This action will go a long way toward avoiding loss of time and money.