Can You Apply a Clear Sealer or Polyurethane over a Deck Stain? 4.9/5 (243)

by Deck Stain Help

Update 2019 for Clear Sealer or Poly over a Deck Stain?

We here at DeckStainHelp.com thank you for your continued support as we continue to be the internet’s number one reference for all things wood deck restoration related. If you have ever considered using a polyurethane coat to give your outdoor wood deck a smooth appearance, read this article and really think about the potential repercussions. As always, we appreciate your input, so feel free to leave a comment below.


Peeling Deck Varnish

Peeling Deck Varnish

Deck stains are meant as a protective finish for exterior wood. They contain special UV shielding pigments and mildewcides to ward off mold and mildew and to keep the wood from fading. Other sealers or clear finishes will not adhere well to a deck stain and may result in the topcoat failing prematurely. Most likely the clear sealer or polyurethane will end up peeling and flaking off the deck stain.

Unlike paint, stains and sealers are not necessarily designed to adhere to each other. Most are designed to penetrate into the wood or at least adhere to bare wood in the case of film forming stains. Applying a clear sealer over a deck stain is never a good idea. It really won’t help the deck stain or give any added protection more than the deck stain already is. Clear sealers have no pigment and therefore provide zero UV protection. The same goes for polyurethane.
If you are looking for a more shiny finish on your exterior wood surface, it is best to choose a deck stain that will give you the appearance you are looking for. Applying a clear sealer or polyurethane over a deck stain will cause more problems than it is worth. If you want a clear finish then you can strip off any old stain and start fresh with bare wood. Then you can apply a clear sealer if that is the look you are going for. Just remember that you won’t get any UV protection from a clear sealer, only water protection.

In addition, applying polyurethane over a deck stain will make it near impossible to maintain the deck down the road. As the deck stain begins to fail underneath the polyurethane it won’t be possible to clean and recoat it without stripping off all the polyurethane first. So can you apply a clear sealer or polyurethane over a deck stain? It is not recommended and should really be avoided if possible.


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Sherry
Sherry

Can I mix Thompsons water seal and water based polyurethane together?

Deb
Deb

Had a bird feeder made (simple pine) & it was sealed with a oil based polyuretherane. Do not like the natural look & want to put a sold color stain on it. Is this possible & what would be a good product to use?

Thank you

John
John

I recently had a patio cover built with pressure treated timber and pine wood. I used a MinWax Espresso stain and it turned out very dark (almost black). I was thinking of applying some sort of sealant or Thompson’s Water Seal for added protection from the elements since it will get a lot of sun in the summer here in Texas. What would you recommend?

Jerry
Jerry

We had a contractor seal our new cedar fence. We wanted a clear coat with UV protection so it maintained its natural look, but not gray like cedar does. He mistakenly applied Sherwin Williams waterborne clear deck sealer, but only after application did I discover that it has no UV protection and the wood will eventually gray. Is the best approach to remove the SW by power wash and sand and start over? If so, what’s a good UV protected clear coat to apply (not shiny)?

Karen White
Karen White

Hello, just had tongue and groove wood added to ceiling lanai . Stained two coats but luckily contractor told me not a good idea to do a top coat like you recommend. I wanted a gloss look like I see online but now I’m thinking those shiny Ceilings are pvc type of planks? Also, could I rub some sort of wood oil or conditioner or wax on it? First photos are inspirational last pick is mine. : (

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Mary Ellen
Mary Ellen

I have a cedar deck floor never been treated, stained etc. I want the wood grain to show thru is a satin polyurethane a good choice?

LisaHa56
LisaHa56

Omg I just put a gallon and not done yet of minwax polycrylic on my deck , then realized it is for interiors only. What can I do now to fix this?

Anne Hersh
Anne Hersh

We have a 1 yr old deck that was stained with oil based S. W. semi-transparent redwood color over pressure treated wood. The wood was pre-stained before installation and stained again after. It has never looked great but a year later its just awful. I got into a debate with the carpenter, as my past experience in other homes it’s quite necessary to leave a gap for drainage between the boards. Well, he finally listened to me but about 25% of the boards are butted right up against each other. Water pools in those areas and the deck is quite shaded. I have tried to clean this, bought a power washer, etc. It gets cleaner but still looks hopelessly stained. It’s a big deal as the deck is 60 feet long. Your advice would be really appreciated. Didn’t want to use a solid stain and everything I’ve read on this site says you can’t apply a sealer over it. Could I apply another, darker oil stain over it?

Dan
Dan

when sealing a deck how many coats of stain should one put on 3 or until it no longer soaks into the wood?

gary zelinger
gary zelinger

I just finished making a small table out of red wood I had for 30 years. I put 2 coats of cabot Timber oil. can I put varnish or polyurethane over the timber oil.. this piece will be outdoors in Colorado

Emily
Emily

So I accidentally bought furniture and hardwood floor wood stain at the store because it was in the wrong section and I’ve been reading paint cans all day. It wasn’t until I was halfway done staining my deck that I realized this. Would putting Thompson’s water seal clear water proofer on the deck help me or should I use a paint cleaner and start all over?

Greg
Greg

Can/should a stain, solid color, overcoat be applied to a deck that has had a transparent water sealer applied first? A hot tub will be sitting on the deck.

Christina Brummett
Christina Brummett

I am using Deck Over by Behr on an “interior” plywood floor. Can I poly over that?

Jeramie Thompson
Jeramie Thompson

I’m building a farmhouse style picnic table. If I apply Thompsons water sealer do I still need to apply a top coat such as polyurethane, varnish or lacquer? Thanks

Trent Harris
Trent Harris

I’m using Sherwin-Williams Super Deck Solid Stain. Have followed all processes and am unhappy with the chalky finish of the product. I’m not willing to start over as my deck is 1,000+SF! Can I apply a Topcoat product over the aforementioned product?

Dawn Bruce
Dawn Bruce

I asked the same question recently because I too didn’t like the ‘flat’ finish and wanted a shinier look,but it’s not recommended to put anything over flood stain. If you find a usable product let me know

Rafael
Rafael

I’m presently doing a deck, I’ve sanded and applied sanding sealer and now saw your article. I was going to stain it and clear coat it. As I already applied sealer should I sand it again and just apply the stain?

Patrick
Patrick

Previous owner had painted the deck and now it is a mess….peeling, mildew, etc. I’m in the process of replacing a few rotted out boards and need some advice as to the best way to remove the paint and condition the wood before I stain it. Will it be a problem to add new boards next to the old ones? Thanks for your help!

Trish
Trish

I have a new deck pine wood it is starting to split it’s only about 6 weeks old and now I’ve decided to use a wood filler . I’ve sanded the deck with a 60 Grit ( I don’t want to use a finer grit because I don’t want my deck to be slippery, I noticed when it rained in an area that I used 80 grit it was slippery) I’m in a sunny location so the deck needs super protection from UV rays and mold cuz I have a lot of moisture( direct sun during the day but high humidity due to the rainy area) I’m done sanding I’m going to go back in and do a deck wash allow that to clean any debris from the sanding and allow it to dry I’m going to use a semi-transparent stain.

2 Questions
I’ve used Elmer’s exterior wood filler natural color. I’m noticing because I have a lot of rain during the process the product during the drying time the product is shrinking.
And the wood continues to split how to prevent this , I understand that this is the process of wood drying out and the deck is definitely dried out my Builder told me I must get a sealer on it ASAP But it doesn’t want to stop raining long enough to allow a 2-day drying pirod. Any suggestions?

Also I want to use a semi-transparent stain and sealer . I understand that being a semi-transparent it doesn’t give it as much protection from UV and graying. Algae mold and mildew is another concern. My question is what product do you recommend for these issues in a semi-transparent and seal product?

Michelle
Michelle

So the local paint store didn’t give me the advice above so I applied Thompson’s sealant over a stain. The deck appears oily now and from reading the info above it appears to be because the sealant has nothing to “grab onto” or soak into as the stain was applied first. Can I apply a degreaser? The sealant has been on for 4 days now. Or do I just let this error I made run it course and strip the deck in a few years when the stain starts wearing?

Brett Strittmatter
Brett Strittmatter

Just replaced 14 boards on my deck. 11 of them are side by side in one section and the other 3 are side by side a few boards over. ALL of the old boards (that I did not replace) on the deck are stained (stained them last summer) and look pretty good. I do not want to strip all the old boards, apply sealant to the entire deck (new and old boards) and then re-stain the entire deck. However, I fear that if I apply water sealant to JUST the new boards before staining the entire deck, I’ll get a situation where if it rains Ill see a lot more water droplets sitting on top of the new boards that have water sealant AND stain while the old boards (that only have fresh stain) wont have as many water droplets and that it would look ridiculous. Although not too many people sit and watch water gather on the deck when it rains haha. Just say the words and I’ll just apply stain to the entire deck (old boards and new boards) and hold off on the water sealant. We plan to sell the house in spring 2020 so maybe the next owners can take the time to strip the entire deck, seal it and re stain it. Maybe the new owners won’t like the stain colors and decide to strip, seal and stain the whole deck anyway. Any feeback would be great!

Frank G
Frank G

After stripping and sanding off old stain, I applied a PPG walnut colored deck stain to the pressure-treated boards on my covered screen porch about 2 years ago. The boards look OK but are dull and non-shiny. I would like to give them some kind of low-gloss rich shine, sort of like the matte finish on an old antique piece of furniture.

Could I apply some kind of wood polish to these boards, perhaps the polish I use inside my house on my hardwood floors? If not, is there anything I can apply to stained boards that will give them a mild shine?

Tania
Tania

I have a new pressure treated lumber deck. Should I use stain or stain with sealant (already in it)? A lot of brands seem to have both but I’m confused about using stain with sealant if stain is supposed to absorb in wood whereas sealant is supposed to sit on top of it.
Thanks!

tina
tina

Hi. I am refinishing some teak and while I like the look teak oil brings, I am looking for more protection. I applied timber oil for the UV and mildew resistance. The matte look is ok but was looking for a bit of shine. Is there anything that will help?
Thanks

Lisa
Lisa

Help plz.. knowing now was not a good idea.. I colored stained my deck boards coated over it with Thompson water sealer. I put the coat of Thursday an here it is Sunday an its soo sticky any help plz

Russell
Russell

I have a 40 year old home with cedar tongue and groove siding. The last two times it was stained with Olympic stain. After reading some of the reviews i am thinking about doing it this time with TWP.We have been mixing semi transparent cedar and redwood in equal amounts to get the color we want. Is this possible with TWP and can i just power wash and stain over the Olympic. It has been about 10 years since last application.

nancymagargle
nancymagargle

I applied Thompsons water seal to my 20 year old deck and it is just lying there on top of the prior stain. I understand I made a huge mistake. Should I wipe it up and hope for the best or what? I’m desperate.

brenda
brenda

i used a clear stain but i got whit pulley now the white is show how can i cover up the pulley? Can i use a darker stain

Mary Scheidt
Mary Scheidt

What paint to paint over a painted deck?

David
David

I bought a house 1 year ago which has two decks both had never been stained or sealed before. The decks were built with treated lumbar about 3 years ago now and I applied one coat of Cabot semi transparent cardovan brown stain last summer (2 years after the decks were built). Before applying the stain I power washed both decks and washed them in deck cleaner then waited a week before actually staining them to provide time for the decks to dry. Both decks were completely dry with good weather conditions so everything sound great right? Well after this past winter the stain has came off the top deck rails and the flooring in streaks/strips and boards are starting to bow. I’ve confirmed the boards are screwed down correctly and even reinforced them but one board has actually bowed enough it snapped the screws. Our house is on a hill exposed to a lot of sun so I guess my question is will stain be enough to prevent the wood damage or extreme warping or will I need to go what a solid color like a deck over to protect the wood with so much sun light. My other question is with the stain coming off just after the winter would a second coat of stain be a good idea or just sand everything down to go with a more solid method to cover/treat the wood and prevent damage or further board replacement?

Linda Brooks
Linda Brooks

I was told I could use a silicone sealer on my deck and I would be able to stain on top after 3 months. Is that true? I like the idea of a silicone sealer but I don’t want a natural wood look. I need to stain the deck to match the porch. What would you recommend?

Michelle
Michelle

I power washed my deck then I stained and sealed it. Now it is scratching very easily. What can I do.

Sandra
Sandra

Can you wash a. Semi transparent paint and apply a clear coat on the deck.?

Myrlii
Myrlii

Can you put exterior deck stain on interior step treads? They are new treads.

Chuck Kuhn
Chuck Kuhn

OMG, I was about to put a coat of clear polyurethane on top of the new Behr stain and sealer that I put on this morning.
Glad you came up in Google, and stopped me from making a big mistake on my deck. Thanks a bunch.

Laurie
Laurie

Can I apply a semitransparent stain over a deck that has been sealed
Lots of info about the reverse step but nothing addresses sealing first

Decker
Decker

I just built a new redwood deck. I like the look and don’t want to color. I put on one coat of Olympic Waterguard and it soaked it up. The deck is scratching easily, is there anything I can apply that would creat a hard protective layer to stop it from scratching and denting?

Nathan Wilson
Nathan Wilson

I used BEHR PREMIUM® Transparent Penetrating Oil Wood Finish on my deck do I need to seal in now with a product like Thompson clear water sealer? or will the penetrating oil be enough?

Cindy Altland
Cindy Altland

How can I remove a sealer from a deck? I applied a thin coat of valspar sealer over deck I stained with rock solid stain and it’s turning white when it gets wet. Can I put rock solid primer over it and restrain with solid color to fix deck. What product will strip sealer if I have to remove it first?Thanks for any suggestions.

Jane
Jane

Put Thompson’s transparent stain over 30 year old, lightly sanded, pressure treated deck support posts. Applied late in the day and it went down to 34 degrees last night. The posts look “milky ” today. Poor absorption due to weather?

Tim
Tim

I stained our pressure treated deck with Olympic Summit solid stain. It shows every foot and paw print and they do not wash off. Even a pressure washer cannot get the job done removing the prints. Is there a different product I can use that will give better results.
Thanks in advance.

Lynda J Reed
Lynda J Reed

Can you apply marine varnish (satin) over stain?
I need the most durable application for a coastal area with high levels of salt and moisture in the air.

From experience I have found that marine varnish is much more water and UV resistant than oil based Spar Varnish. I just want to be sure that stain and marine varnish will have a great look when I am finished.

Lalo
Lalo

I am installing a wood flooring in my livingroom and just realized that I used a stain and sealer. Can I use a floor gloss over it

Gary.p
Gary.p

Hello.
I have read the article…
I just finished using feast and Watson semi transparent deck stain in black Japan.
I have applied 2 coats as per instructions and I am happy with the colour however some parts look flatter than others.
Do I need to add more coats to get more of an even sheen or is it possible to put say a natural oil based decking oil over or some sort of wax ( bees wax or something)
I know you can’t put polyurethane over it and neither do I want to , I was just wondering if there was anything at all that was compatible with the stain?
Thanks in advance
Gary

Tim
Tim

I’d like to correct the previous question. At the beginning of my comment what I meant to say is it is bead board and pressure treated lumber

Tim
Tim

I have a customer who had there ceiling on the back porch and read it is been born and the rafters are Pressure treated lumber. It was stained and now there’s brushstrokes all through it, they want it to be fixed. what would be a good way to do this? Sand it down then re-stain and re-poly? Materials used was a Benjamin Moore arbor coat Semi transparent stain and Benjamin Moore arbor coat sealer clearcoat. Any information on this would be helpful. Thx much

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Ron Lyng
Ron Lyng

I installed a very large Ipe deck about 2 1/2 years ago in CA that looked simply amazing. Stained the deck with oil based stain and cut it @ 30% with thinner to help absorption. The wet look went away within a month sad Re-stained every four months and the deck kept getting darker and uglier. At about 2 years I sanded the deck down and re-stained and now it is getting darker again and looks unappealing. I want the deck to maintain a wet look. I do not see any alternatives. You keep saying not to use a varnish, but that is the look I want. What to do?

Chad
Chad

After staining deck previously with oil stain, it tracked inside onto my carpets. After a month, I had brown paths
in the commonly walked areas. I need to restain deck, but have new carpets. Any suggestions?

Madeline
Madeline

A year has passed and planned on staining a new deck this month but the weather has been unpredictable all summer with a lot of rain. Would the deck be o.k. through another winter before staining it? Hoping for better weather soon.

Anna
Anna

What are your thoughts on water based vs. oil based stains for old but totally re-finished wood? We did extensive experimentation and ended up picking an oil-based semi-clear from Armstrong (thank you for those reviews btw smile ) but the long term argument of water vs. oil is still not settled. It looked to me like the oil was getting absorbed much better and was making the old wood feel/look renewed where the water stain just kind of sat on top of it. Is there a real difference in wood condition and protection between oil vs. water based stain?

Sarah
Sarah

I am wondering what kind of sealer would be best to but on oak to protect it. I am thinking a water based clear color. We built horse stalls out of oak and want to prevent mold mildew urine etc. from turning oak to black.

Beard
Beard

I used Cabot oil it looks wet like fresh wood

John
John

Thank you. I just sanded my 110 year old, never refinished, always painted, front porch floor to bare wood yesterday. Took 7 gallons of stripper to get all the paint off and ready to sand. Bought SW Woodscapes solid stain instead of repainting. Got all sorts of answers from all sorts of people: some saying to poly over, some saying they wish they didn’t poly, and some saying to never poly.

This is the kind of in-depth analysis I have been looking for. If the weather is good today, I’m applying the stain… alone. Much appreciated.