Return to the Porches & Decks Forum | Post a Follow-Up

how long to dry? it's taking foreverrrrrr!!

Posted by cottagecindy (My Page) on
Sat, Jan 14, 12 at 17:44

Hi, I have 3 - 20" squares of 1/4" plywood that I'm going to place under a mattress to make uber firm support. (long story) but the question is-- I used Thompsons water sealer, 2 coats, and it's been like maybe 5 days or longer and it is still a bit damp in some areas i see the shine, and rub my fingers on the areas and get oil on them. I don't get it, they were dry between coats. How long does it take?? I even have them sitting against the garage in the sun (luckily we are having a warm spell here in SF bay area. but jeeeez, I have delayed having the mattress delivered. (God forbid when I do a deck this spring!!) I was told to put a spray of polyurethane (interior use kind) on top when this dries --I have to be 100% not allowing moisture to penetrate the wood. HELP !!!!!!!!!

Follow-Up Postings:

RE: how long to dry? it's taking foreverrrrrr!!

Not sure I want to know why you have moisture under your mattress... but anyway, who told you to put water seal on the plywood? I don't think you can apply polyurethane over that?

I'd start again with marine plywood, sand, and apply an exterior/marine polyurethane. It still might be difficult to seal the edges.

RE: how long to dry? it's taking foreverrrrrr!!

LONG story about the mattress/bed furniture (bad design ) but the boards I am using for support I am waterproofing them just in case moisture gets under the boards-a big boxed in area that sits on the floor. This old cottage has bad insulation and the air goes from cold at night to warm in the day --BIG swing too. and the floor is like frozen ice (no insulation between under the house crawl space, literally just 2 layers of wood,the carpet pad, and carpet. Anyway---sorry not to get into all that, wrong forum topic---but now I'm trying to waterproof/moistureproof the boards the mattress will sit on and I'm soooo not familiar with the sealers. Was hoping you guys who seal decks might be able to help. My planks are just about dry, and I'm understanding (correct me if I'm wrong) so not to bother with the polyurethane over it? My mattress is coming Tuesday--I literally just ruined a $3k mattress due to the center it becoming a valley on cheap thin veneer boards and moisture making puddles either from condensation thru the cheap boards or down thru sweat via the mattress.or air between the board and mattress.... I don't know :( all I know is I'm
1) putting strong plywood down now
2) waterproofing the wood to make a moisture block in either direction
3) putting a waterproof protective mattress cover on the entire mattress. They actually sell those--and they breathe.I HOPE!
4) hopefully all this above will keep my new bed (another $3k bed Tempur) or I will be on the couch for at least another year. :(

RE: how long to dry? it's taking foreverrrrrr!!

1) I wouldn't call 1/4" plywood "stong".
2) It sounds like the last thing you need is to _block_ the moisture - it sounds like you want to add ventilation. Can't you raise the boxed part above the floor so air can get under it?
3) A waterproof mattress cover that breathes will probably stop _liquid_ water but still pass water vapor.
4) I wouldn't put a $3K mattress on wood that has been treated with water seal. Sealing a deck exposed to sun, rain, and snow is different from creating a water barrier under a bed!

RE: how long to dry? it's taking foreverrrrrr!!

Thanks for the advice Dennis. I really do appreciate it. I don't know what to do. On the "furniture" threads folks are trying to help also. I feel like the ultimate screw up. I bought nice furniture from Pottery Barn with a flaw that others have had the same results but I want to keep the bed, so I'm doing everything I can. I guess I can go to HD and get more wood cut. --the reason why it is 1/4" is because it is replacing the old fake wood that sits in the middle of the platform bed- that had no support. The 1/4"plywood is way stronger than the original thank god. plus I am putting cement cinderblocks under it throughout. this is so frustrating... : <

RE: how long to dry? it's taking foreverrrrrr!!

If you can get it all up off the floor by even using 3/4" blocks so that there is an air space without any of it in direct contact. Yor bigger concern should be your crawl space issues as your subflooring is going to deteriorate under the carpeted areas and anywhere haevy objects are in contact. I would address those issues before they become even more of a costly project than what it's going to be now dependent on how much damage might already exist. Depending on your crawlspace construction and layout, you might be able to insulate the perimeter stemwalls and visquine over the soil area and up the stem walls without having to insulate the floor joisting. Less expense and a good way to keep any underfloor plumbing warm. Here's a link, there are many out there.

Here is a link that might be useful: crawl space insulating/moisture control

RE: how long to dry? it's taking foreverrrrrr!!

Thanks for the link. I read it and I may mention something to my landlord about it. I wonder if it is worth it to spend $ on putting insulation under the floor. If it would keep less cold out of the house, since the floor always feels like an ice rink-- and I will be living here a good few years.... I know it's a rental, but money to insulate vs. money on electric bill. Is it a DIY job? the video makes it look easy, but lots of "crawlspace" on the video -mine gets veryyyyy skinny towards the corners and the dirt is not even level. (house is a perfect square shape) oh, and my boards did finally dry. :)

RE: how long to dry? it's taking foreverrrrrr!!

Oh, yes. The wonderful experience of living in the bay area. Your problem is the bed frame has no ventilation. That is the problem with your mattress.

We sweat alot when we sleep. Even in the freezing cold uninsulated shacks around San Francisco, we sweat. All the sweat has to go somewhere. Most absorbs into the bedding and eventually down into the mattress. To dry properly, the mattress must have free airflow underneath. The memory foam REALLY needs ventilation, much more so than an ordinary spring mattress.

Do something to create an opening aroung the bottom of the bed. Have a carpenter cut the bottom, or build a simple pedistal.

Now that I think about it, I could help you. I live in Pacifica, where are you?

I could also give your landlord an estimate to insulate the attic and crawl space of that old house.

I got a nice tax credit last year for doing this to my house. I think I got about $1,000 tax CREDIT. All I had to show was my receipt from Home Depot for all the R-30 and R-19.

Send me and email:


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Porches & Decks Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here