Answers to Deck Questions #1

Q. Last June I used treated 2 x 12's as treads to build steps for my front porch. Yesterday I noticed they have begun to crack and curl to the point that they are pulling up from the stringer, even though I used 3" deck screws. Any suggestions as to why, and what I might do about it?


You used the wrong sized lumber. You should never use anything wider than 8" on outdoor decks or steps. In this case, you should have used two 6" treads instead of one 12". You may be able to remove the treads, cut them in half and re-screw them to the stringer. If they are too curled to do this, replace then with 1" x 6" or 2" x 6".

Q. It seems that when I used a roller on the deck, not the railings, it's darker or has a splattered look to it, on some parts more than others. Should I do another coat to match the tone once it dries completely?

A. It sounds like you are describing the dimpled texture that your roller left on the wood. Another coat would certainly even out this effect, but as you apply more stain it will get darker - if that's what you want, that's great. A roller with less nap may help you avoid leaving too much texture - just watch your lap marks along the edge of your roller, rolling over them so as to eliminate any dark lap marks.

Q. I just had someone build a 16x24 foot deck extension. He did a great job overall, but I have one question. He used four 4x6 posts to hold the 24-foot width. He used 2x10's 16 inches off center. However, he didn't notch (right word?) the 4x6 where the 2x10 header ran. He used four nails in each 4x6 post. He said this would be stronger than notching out the 4x6. I'm just inherently suspicious about nails holding weight. I'd like him to go back now and use some large bolts to fasten the 2x10 to the 4x6 posts. However, I am no carpenter. He insists that the deck is extremely strong and that no bolts are needed. Is he right? Is there a building code section or some other authority I could refer to?

A. He should have notched the posts for the 2x10 beam to sit in as a bare minimum. He should have used a double 2x10 for the beam and had it sitting on the top of the 4x6 post. The nails won't hold squat - have him put at least three 3/8" or larger through bolts through each of the posts and 2x10's.

Q. I am building a new pressure treated wood deck, 24' across the back of the house, 14' out. What kind of slope should I put on it? How much drop in 14' would be sufficient?

A. Did you check your building code there? Some people like just 1/16 per ft., which is 7/8" for the 14ft.

Q. I don't want to use pressure treated lumber, so I'd like to ask about the alternatives for treating the wood, what works best, and what the difference in longevity will be. I'm limited by a budget so I would probably be using 2x6 Doug fir for the deck floor, or whatever the common wood is that one finds easily. Any opinions about wood would be best? I do know about redwood but it seems to cost about twice as much as the standard Doug fir available at a lumberyard.

A. For the framing (posts, girders, joists), you have about three choices - use pressure treated, use Doug fir and spray it with copper green, or use Doug fir and paint it. For the decking, you have about three more choices - redwood, a composite, or vinyl. Do not use Doug fir for the decking and try to seal or stain it. That's a waste of your time and money. You'll be replacing it in about five years. Using redwood, it'll cost about 40 to 50 percent more than Doug fir, and sealing it regularly with a good stain or sealer will last about 15 to 20 years. A composite or a vinyl is going to cost you more than redwood initially, but you won't be staining or sealing it every year or two. After about 10 years, you are money ahead. The more you put into the deck up front, the less you'll be putting into it later.

Q. I have a cedar deck that has been stained with Sikkens. It is a mess with the stain peeling and lifting in areas. I have sanded the bad areas, but cannot get an even clean finish. I want to apply anything over it that will cover the existing stain that is left on the wood and have it look acceptable. Can you apply stain over stain?

A. Don't just re-stain over it. What type of Sikkens is on the deck, and how old is it? The maintenance procedure for Sikkens is to use the recommended cleaning solution. Power wash with no more than 500 psi and then slowly build up the film to match the intact coating, i.e., apply a coat to just the bare wood spots. Let dry 1-2 hours and apply another coat to those spots. Wait to dry, and then recoat the entire deck.

Q. My wooden deck is attached to the house at slightly above ground level. In my basement, the bolts that attach the deck to the rim joists of my house (the large beam running under the exterior wall, to which the floor joists attach) are visible. After heavy rains, there is wetness around these bolts and on that beam in the basement. There's no dripping water, but the beam is visibly wet. I can't see the junction between the deck and the house, but I wonder if it was properly flashed. I'm going to try to crawl under the deck to get a good look, but my questions are:
What should I be looking for?
If flashing is there, it's not working. What should be done?
If flashing isn't there, how can I add it without removing the deck?
Is there any other option?
Who would I call for this kind of work?

A. You should have flashing there. When the home is built they bolt the joist hanger two times for the deck to the belt board of the home. A piece of sheet metal flashing that looks like an L with a small foot down on it should go on top of it and be under the siding of the home. The deck boards would go on top of this. This way, no water can get down there between the belt board of the home and the joist hanger for the deck. Pull some of the deck up next to the home and fix this. Flash it; don't try to caulk it.

Q. We just finished a deck made of premium Redwood. When a storm hit, we were told to keep it dry, so we covered it with tarps. Well, some water got through and now we have spots of water stains. What is the best way to get rid of these stains, or are we stuck with them? We have not had a chance to seal the wood yet.

A. Oxalic or citric acid will remove the stains and even out the color of the wood.

Q. I have a deck attached to my house. I would like to put a California roof on it. The deck is 16'x16' and is about 10 years old. Can I put this on the deck and if so how?

A. No reason that you can't. Just start at your local building department so that your attachments will be done in a manner that they will approve of, and the cover is done so that they will approve it.

Q. I have an elevated deck off the back of my house, which gets no sunlight underneath, resulting in absolutely no grass growth, which turns into mud when it rains. Here's the problem: My septic tank is under the deck, so I am limited to what I can put down to where I can still dig up my tank to get it pumped out when needed. Got any ideas of what I can place down but still allow easy access to the septic tank? I was thinking mulch or gravel of some type?

A. Dig up the tank lid and install a riser so the lid is on grade. Then use landscape fabric and mulch or stone. Many folks enclose beneath the deck area with lattice or other material and use the space for lawnmower and lawn equipment storage or a potting shed.

Q. We have a deck we must stain every year. My husband and I both have bad back problems, and he has bad knee problems, so this is a major chore every year, and we both hate it. Has anyone ever heard of carpeting a deck with indoor/outdoor carpeting?

A. I know a carpet on a deck is generally not a good idea. You'll get moisture trapped between the carpet and the decking and the boards will rot. Trapped moisture beneath carpeting tends to place wood decking in danger of rot and decay. I just saw a friend remove it from a wood front porch. The decay was a dreadful sight to behold. Going with a better quality sealer would prolong the periods of resealing. There are some new composites decking materials available, but they, too, tend to succumb to environmental factors in the long run.

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