# Stain both sides of deck boards



## marly (Nov 14, 2008)

I have all my deck boards off my deck, so it’s pretty easy to stain both sides. Is there any advantage to staining both sides? Would it would it make them last any longer?


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## Matthewt1970 (Sep 16, 2008)

I actually think you can shorten thier life. Water WILL penetrate the top layer of stain one way or another and a coat of stain on the bottom can make them take longer to dry. You basicly are trapping moisture in the wood.


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## jsheridan (Jan 30, 2011)

Depends on how high they sit off the ground. If they are 12-18 inches off the ground it may benefit. Untreated boards that close to the ground can simply be transfer vehicles for ground moisture. But, beside that, if they get no direct sun or rain/snow exposure they should be okay without.


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## Faron79 (Jul 16, 2008)

JS hit on the head there!!

YES...by all means....stain both sides when you've got the chance!!!

Because:
* As JS notes, and we all know...wood absorbs moisture. Simple as that.
* By staining ALL sides, you keep most of the moisture OUT. 
* For low decks (even up to ~4' high), and skirted-in styles....GROUND-MOISTURE vapor, and atmospheric vapor "hang" under decks, and penetrate up into the wood.
* This obviously contributes to film-lifting and wear.
* For example, Sikkens DEK-Finish is a FILM-BUILDING stain...NOT a penetrating type like SRD. 
* To maintain the sheened film of DF, Sikkens REQUIRES ALL sides to be coated TWICE. 
* WHY?!?!?.........To keep most moisture OUT in the first place, so it can't "push-off" a film-building finish!!!
* BUT....even DF has its limits. Sikkens also says NOT to use this type of finish on any deck under 3-4' above ground.
* I realize you're probably not using DF, and most likely using a penetrating S/T stain, such as Sikkens SRD.
* Same principal applies though....the more H20 you can keep out of wood in the first place.......!
* Water dries off the topside fairly quickly. Vapor leaving the ground under a deck (and INTO the lumber) is relatively CONSTANT. Summer air obviously holds WAY more water than cool/winter air anyway.

>>> Bottom-line:
The closer your deck is to the ground....the more important it is to get that bottom-side stained!

This is also why 'Back-priming" used to be ROUTINELY done many years ago.
>>>> To keep moisture OUT of the back of wood siding materials, and lifting the surface film.

Faron


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## Cpcphil (Jul 2, 2012)

I totally agree with Faron on this one. Keeping moisture out of the wood is key to keeping a coating on the wood. Most semitransparent coatings are designed to breathe (that is let moisture escape from the inside out) The exceptions to this are film forming products which I am not a big fan on for horizontal surfaces such as decks and the tops of rails. The simple reason is that a coating that forms a film on the surface will eventually crack and peel and maintenance becomes a chore rather than cleaning and recoating with semitransparent stains.

Even still coat all six sides of your deck boards by all means!

good luck....


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