Finishing a new deck, backfilling a foundation
Do not simply apply a deck stain to your new deck and hope for the best
FINISHING A NEW DECK
Question: What’s the best option for finishing a deck so it has that sealed, wet look, like varnish? We have a new cedar deck and I was looking at TWP products for finishing. I understand the moisture content of the wood needs to be below 15 per cent.
Answer: I don’t have firsthand experience with TWP finishes, but I do see some decent reviews by people who have actually used it. That said, I know that many deck stains don’t perform well no matter how well you apply them, so caution is in order.
I’ve run an ongoing deck stain field trial since 1990, and you can see the up-todate results on my website at baileylineroad.com/ deck-stain. There are a handful of options there. Of the products I know, Sikkens DEK creates what I call a furniture-grade deck. If you’d like to try TWP, I’d start by applying some to test boards (scraps left over from deck construction), and see what it looks like. This won’t tell you much about how well TWP lasts, but it will at least show you if you like the appearance. Many people I hear from are disappointed as soon as brush touches deck because they didn’t take the time to create test samples. Without beginning with a sample, you’re committed as soon as you begin. Live with the sample boards for a while outdoors and see how the product stands up. There’s no rush to apply a finish because you’ll need to prep the surface whether you stain now or later.
Fifteen per cent moisture content is the typical maximum for outdoor wood being stained, so you should pay attention to that. Moisture meters are so inexpensive these days that it’s a great idea to buy one and see exactly what your wood is like, moisturewise.
One last thing, and it’s crucial. Do not simply apply a deck stain to your new deck and hope for the best. New lumber is not absorbent enough to allow stain to get a good grip on wood fibres. If you don’t prepare first there’s a good chance you’ll get premature peeling of the finish. My favourite prep method begins with pressure washing followed by sanding with a 60- or 80-grit abrasive in a six-inch random orbit sander when the wood is completely dry. Apply your finish on a cloud day or in the shade.
BACKFILLING A FOUNDATION
Q: What’s the correct way to backfill around a foundation? Are there specific layers of different materials that should be used? As for grading, is there more to it than simply sloping the soil away from the building? A: Backfilling is not complicated, but it also involves more than just pushing any old kind of soil back around the foundation walls. The best backfilling jobs include three features: waterproofing of the foundation walls including a moisture-proof layer with a vertical drainage membrane such as Delta FL; drainage tile at the bottom of the foundation wall; and the right kind of soil for the actual backfilling.
Generally speaking I recommend light soil for the majority of the backfilling to allow the free downward movement of water through the soil and into the drainage tiles. Putting 12 inches or so of heavier soil on top, sloping away, helps shed water away from the building as much as possible.
Before you begin backfilling, put ¾-inch diameter clean crushed stone on top of the drainage tile, with a layer of landscape fabric surrounding the stone to stop silt from clogging the spaces between the stone and the drainage tile itself. Follow this crushed stone up with sand, then a cap layer of heavy loam with a high percentage of clay to shed water.