To cover the wooden deck or not, that is the question.

[network_engineer]

Hi all,

We just built a wooden deck and applied about five coats of stain (Valtti) on it to prevent it from getting spoilt. I.e. I did apply about one to two coats of stain to the frame (runko) underneath, and then five coats to the deck boards.

Now, I was wondering, would it help even more, if I were to cover the whole deck with plastic sheets for the winter time? I.e. my line of thinking, no snow falls on it, no water goes in etc. and so it gets better protection. On the other hand, I am confused if putting the plastic on the top of the deck would actually not give it any air, since the plastic would create a blanket of sorts - but then so would the ice. The underneath of the deck, obviously, remains open.

Any experiences or advice, particularly knowledgeable ones, would be greatly appreciated.

Thanks.

Kind regards.

[rinso]

Don't use plastic, that would accelerate the decay.

[Cod]

essentially you're building a 'type' of roof..a cold roof (as opposed to a warm roof)

..so it's possible, but you'll need to ensure plenty of ventilation beneath the sheet , so rising damp air condensing on the underside of the plastic is evaporated off by the airflow..(same as a zinc roof etc)

Downside is that the whole setup will probably look pig ugly and your neighbors will slash your tires

[Rosamunda]

We have never bothered to cover our deck in winter and I don't think I have ever seen a deck that has been covered with a tarpaulin. Snow is a pretty good insulator, no need for plastic. The other problem with plastic is that it will freeze onto the deck which means you won't be able to peel it off until the Big Thaw (one reason why the Finns leave their Christmas fairy lights in the yard until the spring time.... the cables are frozen onto the ground). OTOH if this winter is like lasts year's there will not be a Big Freeze anyway.

[DMC]

We are just renewing our covered deck. The previous owners of our house had covered the original deck with a form of waterproof plywood-style sheeting. Horrible basically. Anyway, the folks doing the repair work say that this sheeting is responsible for the extensive rot in the support structure, due to the lack of air flow. We are having to replace all the joists, side timbers, plus the posts that support the balcony above. So experience here says not to cover it.

[network_engineer]

Hi all,

Thanks for the reply! Got it - so we leave the deck as is, without any cover. Come to think of it, I haven't seen any of the decks around my place covered either.

One more question if I may: Is there something else that we should do, such as applying something else other than the Valtti Color kuultava puunsuoja?

Thanks a lot.

Kind regards.

[EP]

Is there something else that we should do

No. Except you could showel the snow off every now and then. So that all of it it does not melt on top of the deck. If there will be snow which nowadays of course is not guaranteed.

[raamv]

but you still need to apply one coat of oil at least every 2 years to keep the wood safe..

[Mattlill2000]

Because its pressure treated wood, it doesn't really need anything appied on it except for looks. You'll pretty well have to apply a yearly maintenence coat on the exposed surfaces with the same stuff you just applied.

[Pursuivant]

or then you can whine how expensive it is and whine some more when you need to have a new decking installed in 5 years

[jas_rho]

The reason the wood is pressure treated is to help it in the weather. So no, you don't need to cover it. Actually its too late but if you just built the deck you should have waited this season before oiling/painting it. When its fresh from the lumber yard its still quite wet deep inside and its good for it to dry a bit. Then after you first season you put a good coat of oil on it and do so about every year or so. Anyway, basically its just like Mattlill2000 said.

[network_engineer]

Hi all,

Thanks for the help - appreciate it.

Now, here's another thing: Just yesterday after the rainfall, I noticed that a small part of the deck is holding the water in, i.e. the normal spacing between the frames under the boards is about 60 cms. However, in one place it is about 80 thereby creating a slight bend, which is what I fear is holding the water in. Double !!!

Any advice? How likely is it to cause the wood to root? I've been swiping the water away at every possible opportunity, but am a bit worried!

Thanks.

[Pursuivant]

not that likely... as said the treated wood is quite impervious... lets put it this way, I have a walkbridge made out of some old 2in planks that are abt 8 wide and some 2x4... all untreated wood except I burned them with pitch... been there for some 10 years now without much maintenance except I need to readjust the free end in the spring after the frost thaws...

[jas_rho]

80cm distance between the boards is quite a lot. I would do 60cm max and that also depends on the thickness of the top boards, the thinner they are the more support they are going to need underneath.

Anyway, in your case, I think you better keep someone on full time alert to brush any water from staying on the boards. Or better yet, build a roof and walls around the whole deck, then you never have to worry about it getting wet

Hopefully you understand that I am joking about that full time alert. The reason those boards are pressure treated is so they can be out in the weather, so they can get wet, and they won't end up rotting. Its ok to relax, even if its raining and your deck is getting wet

[network_engineer]

Thanks all! Appreciate it.