Ask the Carpenter: Removing algae from a composite deck
Ask the Carpenter’s Rob Robillard offers tips for prettying up a garage and a deck. Get more home improvement advice at realestate.boston.com.
Q. The Trex deck we installed two years ago gets covered with dirt and algae. Last summer, we cleaned it using a mix of ammonia, water, and dish soap. The rigorous brushing removed the dirt, but not the algae. What “brew’’ or cleaning products do you recommend we use, and how should they be applied?
ROB MAIDMAN, Sharon
A. I’m surprised that your “brew’’ did not take care of it. It should remove the algae, but it won’t stop it from reappearing. If debris, such as pollen and dirt, is allowed to remain on the deck’s surface, mold can feed on the biofilm.
I suggest a second treatment using warm, soapy water and a soft-bristle brush. You can also try using a pressure washer set at a maximum of 3,100 pounds per square inch. Make sure you use a fan attachment to avoid scarring the decking.
TIP: when using a pressure washer, do sections or one board at a time. Keep the fan attachment 8 inches off the deck, and use a sweeping motion.
Q. We live in a 1940s brick Cape with a garage at the back of the house. On either side of the garage entrance are concrete “cushions’’ presumably to protect the foundation from being struck by the entering car. The problem is that the low bumpers found on modern cars hit them. Also, because the garage is in the back, it is very difficult to enter it with the car straight. Can I have these removed, or would that affect the foundation?
KUNAL JAJOO, Brookline
A. Oh, my. Those “cushions’’ look horrible. Yes, you can remove them. You can chisel them off with an SDS rotary hammer and then patch the wall, if needed.
Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business. Send your questions to [email protected] or tweet them to @robertrobillard. Subscribe to our free real estate newsletter at pages.email.bostonglobe.com/AddressSignUp.
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