We’ve removed the old deck surface, fixed up joists, butyl taped them and are just about ready to put the new surface down. I get the impression that most people lay down the new wood and then stain/seal. I am considering the opposite, though it be more painstaking. I want to stain and seal each new plank first and then screw them down as each board is dried. This way any water that drips between boards has no ingress into the wood, or so I believe.
Am I going overboard with this methodology. Since I’m getting a delivery of fresh boards, I’m not 100% sure all I need to do is apply the sealant. I’m planning on using Behr Premium Semi-transparent Waterproofing Stain & Sealer.
Any helpful hints appreciated.
I should add that recycled plastic boards are a no-go because our joists are too far apart and I do not wish to add new ones. Plus my spouse does not like the look of that material.
I am far from an expert, but I thought you weren’t supposed to apply stain or sealant to fresh wood since they have a “finish” on them from the mill that you’re supposed to let weather a bit.
Also, I’d think if you stained/sealed first, that would work except maybe the wood exposed by the screw, which is a place water might want to pool anyway, since it’s likely to be a small recess, would be more vulnerable. I guess you could dab a drop of stain on those spots after installation, although that might be overboard.
(And I’m no expert on any of this.)
What are these boards made of, what are their dimensions? If they’re pressure treated they don’t need more waterproofing. Staining the boards ahead of time could result in warping and other changes to the shape of the wood that you don’t want. For that reason alone it’s advisable to get wooden planks secured to the deck as soon as possible before simply drying changes their shape. You can certainly get them well coated with stain top and bottom after they’re in, and generally staining the top takes care of the sides unless you are leaving no space between boards (occasionally recommended for pressure treated wood which will shrink up some over time). But a reasonable space between boards promotes drying which is the proactive way to prevent rot.
I’ve built many decks. The official line is to let the boards weather for at least several months of hot weather before staining, some companies say to wait a year. Pressure treated boards do not really need more protection although I am sure it helps somewhat. I built my deck in 1987 from plain pressure treated wood. No stain. It’s under the trees and I get mold on the roof, sidewalks, etc. The deck is just fine after 33 years.
Of course it looks really nice with a stain. My neighbor pressure washes and re-stains his deck every few years and it looks great.
Dennis
You are presumably using “ground contact” grade pressure treated wood, which has a very high moisture content from the treatment process (unless kiln-dried). As mixdenny says, not only does it not require any stain, if you want to stain it for cosmetic reasons it’s a positively bad idea to stain it until it has had time to dry out thoroughly - at least months, possibly up to a year.
The boards will indeed be pressured treated ground contact grade wood. The previous deck was over 22 years old and suffered from rot even though it too was pressure treated, and later either stained or painted. We could never quite figure out which it was.
So the consensus is to just screw those suckers down and let the sun work on them for a year.
We do want to change the look for aesthetic reasons. So then, do we just use a stain/sealant? I do not want to use paint.
I was told by a contractor that it is not a good idea to use pressure-treated wood in any application that will have direct skin contact – such as deck boards if anyone will be barefoot, or tops of railings that will be held by bare hands – because of the chemicals in the wood. I don’t know if they are still using arsenic as one of the chemicals in pressure-treated wood, but in any case, is it safe for frequent contact with bare skin? How about pets?
The EPA banned the sale of arsenic-treated lumber in 2003. New pressure-treated wood is treated with one of two different copper-containing compounds. Read more here.
This report about ACQ-treated wood (one of the “new” types of pressure-treated wood) comes to the following conclusion:
“This risk evaluation included all chemical components of ACQ Type D that might be present on the surface of ACQ-treated wood. Overall, the results demonstrate that exposure to copper, DDA Carbonate, and MI/MCI from ACQ Type D from the surface of treated wood are not expected to be associated with any adverse effects to adults or children who might come into contact with this product.”
I wouldn’t worry about it for children or pets based on that, but then I just used it to build a garden bed (which is also deemed safe - any copper that leaches into the plants would kill the plants long before the copper did any damage to a human).
I guess your statement is probably correct in the relative sense that copper isn’t all that toxic to humans; but copper isn’t especially harmful for plants either. It’s much more toxic to most bacteria and fungus. It’s a commonly used fungicide that’s sprayed on fruits and vegetables for human consumption. It’s even “allowed” on organic produce, for what little that’s worth.
Thank you for this information. It makes me wonder about the contractor who told me that.
What kind of wood are you using?
I have ipe decking, which doesn’t need treating at all. It weathers to a natural grey.
For barefoot friendly, you could use something like Accoya, which is pine treated through a process of ‘pickling’ using a non toxic vinegar - this pushes out the water content, so the wood doesn’t warp, crack, splinter or get hot. Perfect for decking, it’s tougher than hard woods. You can stain it if you want to, but it isn’t necessary. If I was getting my deck redone, that’s what I would spec.
If you seal the deck board totally (all sides), you may hamper water getting out (lumber is not totally dry, some may be quite wet and thus heavy). Also as the top layer wears from sun/foot traffic, scrapes etc, you may get water penetration on the top that, due to the sealing on all sides, can’t leave via the bottom/sides. Basically you may create a ‘bathtub’.
Ideally you should use boards that have been freshly unstrapped. Always install the boards when they are wet and they will dry fairly straight. If they have dried too much when you buy them they will be warped and it is hard to pull them straight. We had tools that hooked over the floor joist and levered the boards straight. I also made a hydraulic ram that did the same thing with more travel and power.
It’s hard to keep the leading edge of the boards straight on a large deck. The tendency is for the ends to be easy to fix in place and so the center of the build grows outward as you go across the deck. Use a string often on the leading edges to keep up with it. If it grows too much to easily correct you have to chalk a straight line on the leading board and trim it back with a circular saw, then route the edge with a round-over bit.
Dried boards are also harder to put screws in and tend to split if you are near the end of the board. Unless you are using some propitiatory system don’t use any screws except star drives. Phillips are terrible and square drive screws aren’t much better and the bit sticks in the screws. Dennis