Should I treat my deck?

August 3, 2005 5:12 PM

How can I tell if my deck needs to be treated?

When we bought the house there was a small two story deck on the side. I have no idea what kind of wood was used. Underneath the second story there is green between the boards. Does that indicate anything? How can I tell what kind of wood it was made with and if I need to treat it some how?

Thanks. Sacre_Bleu's wife

posted by sacre_bleu to home & garden (11 comments total)

Does the water bead up or just sort of lay there?
posted by fixedgear at 5:19 PM on August 3, 2005

We just moved and I have this exact same question! On my deck, the wood is grey, and water just lays there and soaks in almost immediately. I'm pretty sure that it needs to be treated, but I have no idea what with.
posted by the_W at 7:36 PM on August 3, 2005

Is the green a growth, or is it like a stain on the boards? If the latter, then changes are it's pressure treated timber. You're in the US, so it's likely PTDF (pressure treated Douglas Fir).

There are a number of treatments you can put on it, if it's PTDF; the best, for my money, is Penofin for Pressure Treated Wood. Others tend to need more frequent re-treating, or are just plain crap. Cabot's has good products, but are more pricey.

If the former (growth), then you may want to have it professionally treated, and checked for rot and weakness.

It really all depends on what kind of wood it is.
posted by 5MeoCMP at 8:14 PM on August 3, 2005

s/changes/chances/

Darn it.
posted by 5MeoCMP at 8:14 PM on August 3, 2005

the_W,
What 5MeoCMP said abbout professional treatment, or at least assessment. You say your deck is already soaking up instead of repelling water. This is not a good thing for wood! The grey look is caused by neglect. If you expect it to survive, you might want to get it weatherproofed, especially before another winter. Then schedule regular maintenance.

Sacré Bleu's wife,
Is that moss/mildew/mold growing on your deck? These organisms are destructive.
posted by Cranberry at 9:08 PM on August 3, 2005

Typically, all you need to do is pressure wash it, let it dry for a few days, and then stain it. If you aren't sure how to do that, or aren't the handy type, you should hire a professional. But when they're doing it, pay attention to what they do. It is a relatively easy (yet very time consuming) thing to do yourself, and you probably will need to do it every couple of years (depending on how much exposure/use it gets, of course.)

As for stains, I've had good luck with Benjamin Moore and Sikkens brands. I've heard many people say that Thompson's doesn't last very long, but haven't tried it myself.
posted by spilon at 7:38 AM on August 4, 2005

Second spilon's comment about a professional; my girlfriend's landlord hired a few spastic moneys (based on the quality of their work) to pressure wash and stain the deck on the house she rents and it looks horrible. You don't want to half-ass it, it makes a big difference.
posted by phearlez at 8:18 AM on August 4, 2005

My research - online, and speaking with other (handier-than-I) deck owners - tells me that power-washing is never a good thing to do on a wood deck (I can't find links, but googling "deck maintenance" might help). The thing to do is wash the deck with an oxalyc acid cleaner. Use a hand sprayer and scrub brush. Rinse well, and let dry for at least 24 hours. Then apply a water seal - with or without stain, depending on the look you want. I used Thompsons (without stain), and it worked really well - now the water beads, instead of getting absorbed. Also, it did darken the deck slightly.

As I recall, if the deck is gray and starting to split, you might have to re-finish first.
posted by ObscureReferenceMan at 8:37 AM on August 4, 2005

We pressure wash the deck, scrub it with bleach and use Thompson's Water Seal. Water beads nicely, deck is now much lighter in color than it was. It needsto be done every two/three years.
posted by fixedgear at 4:56 PM on August 4, 2005

fixedgear - I've heard (sorry, still can't find links) that chlorine bleach is TERRIBLE for wood decks.
Just curious - how did the pressure wash work? My friend managed to sprayt a funky pattern on his deck.
posted by ObscureReferenceMan at 5:24 PM on August 4, 2005

Just helped to re-do my Mum's decks. We used a pressure washer and restained with Cabot's. It has to be redone every year (Pacific Northwest, very exposed decks).

Pressure washer works fine - to avoid patterns you just need to start out gentle and adjust the pressure as you go along. A decent machine (Karcher) costs about $180 USD at Lowes (she bought her's on sale for $150).
posted by deborah at 2:20 PM on August 6, 2005