Can You Apply a Clear Sealer or Polyurethane over a Deck Stain? 4.9/5 (455)

by Deck Stain Help

This post was updated on January 18, 2022

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 the 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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emmanuel
emmanuel
1 month ago

thank you guys for the reference, am very much interested on this part of the reference| Clear sealers have no pigment and therefore provide zero UV protection. The same goes for polyurethane. i do a lot of painting and staining, and therefore i like researching and learning new things. I bought a clear sealer for my fence, and right on front of the package it says: WATERPROOF, MOLD AND MILDEW RESISTANCE AND UV PROTECTION. am therefore a little curious when the article says clear sealer do not give UV PROTECTION. i will be very grateful if someone can elaborate on that.

Last edited 1 month ago by emmanuel
Betty Jenkins
Betty Jenkins
2 months ago

I applied deck stain to handmade bed. Can I use a paste wax to give it a more finished look

Ben griffy
Ben griffy
3 months ago

We stained our old deck with semi solid deck stain with sealant. Can we apply water sealant on top of it for extra protection?

Ty Jepson
Ty Jepson
3 months ago

My client stained his fir mantle and a fir shelf in his brand new house with Sico proluxe.
What can I put on it to give it a smooth furniture feel?

Tim
Tim
3 months ago

Just stained a tongue and groove ceiling in a covered outdoor patio w a semi transparent deck stain. I’d like to give it a little more sheen w a clear sealer…do I really need to worry about peeling? Obviously with it being a ceiling it won’t see any sun or foot traffic.

David Searls
David Searls
4 months ago

Hello was googling from UK about protection and stains and came across this helpful site.

The old pine window of the pine conservatory was rotten. The whole of the conservatory looks to have been stained with a dark teak when all new. I have made two replacement windows using recycled pine, to fit in the old windows slot (two because a new boiler flew meant original window did not open). The new replacement pine is a mixture of old/new salvaged pine and untreated pine. First time have made windows or anything (apart from decking) to be exposed to the elements. And did not think of issues relating to stains/preservatives/coatings etc. Just thought I could apply deep preservative and then tint or other way round. 

Apart from slight difference in color between the pressure treated and untreated pine parts, the New windows seem nice and solid, would like them to stay that way and also blend in as much as possible with existing dark wood. Does not have to be perfect match-up as old conservatory is a bit higgledy piggledy in any case.

Somehow have ended up with a mixture of stains and oils. I also have some clear Decking Preserver, which I previously used on some decking some time ago and it seems to be good
stuff.

I tested the teak stains “Ruskin’s Interior & Exterior Wood Dye – Penetrating stain for all new or stripped wood” on some off-cuts and two coats seems to give a near enough match-up. The stain says it can be diluted with white spirit so I guess it must be an oil based stain.

The instructions on the Decking Preserver indicate that it cannot be over-coated. And that it should not be used on timber that has been treated with a preserver.

Main concern is with giving new windows as much protection against the elements and rot as possible. i.e. the preserver I already have. But if I apply the oil based
stain first to get the color I want, will this prevent the preserver from fully working?

Hate waste and like to use things at hand, but maybe this is not possible this time after reading some of the comments here.

Before I buy and hope for good match-up, is my only option to try and get some preservative with the same color as the existing conservatory.

Thanks for any help.

David Searls
David Searls
4 months ago
Reply to  David Searls

Thanks for reply. So does the stain also act as a preserver? Mainly concerned about the new bits of timber which were not pressure treated when I got them.

David Searls
David Searls
4 months ago
Reply to  David Searls

Sorry, I suppose the answer is in the fact that the stain is for “exterior” use. I guess that
implies protection.

Thanks again.

Lucio DaMotta-Santos
Lucio DaMotta-Santos
4 months ago

Hi, I stained my house and I used the stain to do my breezeway deck can I apply a sealant to protect it?

Dale Patterson
Dale Patterson
4 months ago

I power washed my deck and most of the stain came off I want to know if I can seal it or re stain it

Brenda
Brenda
4 months ago

My small deck is 3 years old, never had anything put on it. After powerwashing it, I really like the colors that popped out. Blendings of gold, red, and green. They faded as it dried. Anything I can put on it to bring out those colors and then a recommendation for a sealer to protect it?
?

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Diane H Dockeney
Diane H Dockeney
4 months ago

We did a solid dark gray stain on a new deck. Love the color but it looks dirty and you can see every footprint. I have spent lots of time cleaning with deck wash and water but this seems never ending. Anything you can suggest for a easy cleanup?

Dale G
Dale G
5 months ago

I have a deck at a remote location by the Atlantic Ocean. One of them was stained with solid water based stain years ago.

I was wondering if I no longer want to keep putting solid stain on it, 50% pealed now can I put Thompson’s water sealer over it for this year to help protect it from water this year?
We come here every year for 3 weeks and running out of time to try to strip it all off, not to mention it is 12 feet off the ground so striping will be a big job.
I don’t care how it looks but if applying water sealer helps that’s all I can do right now. I power washed off what I could already.

Thank you in advance for your support.

Dale G

Charles vinson
Charles vinson
5 months ago

What can be used on deck to give wet look it has been stained couple years ago or longer not sure it has a Thompsons water seal on it but customer wants a wet look what to use What to use any ideas hum?

Maya Thomas
Maya Thomas
6 months ago

I am leading a team to build benches with 150 year old oak barn wood for my Eagle Scout project.The wood isn’t stained but is a beautiful dark color when wet. From what I have read, I think I can use a clear, oil-based, polyurethane. Is that correct? The benches will be outside.

Maya Thomas
Maya Thomas
6 months ago

What would you recommend for a protectant then? I do not want to stain it, I only want to protect it from the elements.

Rae
Rae
6 months ago

Can I add a dark regular stain to a deck sealer? If the sealer is water based I could use a water based stain.

J. Vaughn
J. Vaughn
6 months ago

I live in an apartment where I’ve taken up the old carpeting and stripped the glued padding. Now I found they actually used deck wood in this room (don’t ask me why). I’m going to sand it and clean it but would like to paint it and put polyurethane over the paint. Can you think of a better way to deal with an indoor deck floor?

J. Vaughn
J. Vaughn
6 months ago

Are you sure about that?

There are hoards of videos on YouTube showing you how to poly over paint.

Joseph Zalatan
Joseph Zalatan
6 months ago

I just purchased a wooden swing set for outdoors is it OK to stain and then put polyurethane on it what do you suggest

Debra Rizzo
Debra Rizzo
7 months ago

I Had My Deck Rebuilt, With Brand New Decking, And Railings, Let It Cure For A Year With Nothing On It, Then Used Lowes Valspar Semi-Transparent One-Coat Exterior Stain & Sealer, 1 Year Goes By, The Following Summer, I Am Hosing It Off My Just A Garden Hose, No Pressure, And The Stain Literally Peels Right Off, So I Sand, With A Palm Sander The Top Rail & Floor As Much As Possible, Hose The Saw Dust Off, Now Am Using Olympic Elite Solid Stain & Sealer, Should I Put Down Two Coats On The Floor?? Also, Do I Need To Seal This On Top To Keep It Beautiful!! The 1st Photo Valsar, 2nd Photo Peeled, 3rd Photo Olympic Elite!

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Dave
Dave
7 months ago

Hi I live in Ontario Canada and I have a problem with my deck.
I completely sanded the deck last year and applied a Home Hardware stain that has a plant oil base.
The stain went on well however the this spring where ever there was a knot or imperfection in the boards the stain came off.
I do not want to sand the deck again so looking for a product to cover the knots and imperfections and apply the same stain or a product that I can apply over the complete deck.
See file for picture.
Thanks,
Dave

Deck 1.jpg
Gerry
Gerry
7 months ago

I have a 5 year old deck. I stained it a dark brown. Everyone around me has bird feeders. The birds sit on my deck and poop!!!!! YUK. I have a hard time cleaning it off the deck and railing. I want to put a clear coat on the deck to make cleaning it easier. what can I use????

Matt
Matt
7 months ago

Applied restore a deck stripper and brightener. Am I ok to apply stain after 48hours of drying? Is this the way it’s suppose to look?

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Matt
Matt
7 months ago

Thanks! Suppose to get rain every other day for the week is it ok to wait to stain?

Matt
Matt
7 months ago

I stained deck 2 coats wet on wet of twp100 it rained about 36hr after do I need to put another coat on it or do I just leave it? Or is there anything I have to do before adding another coat?

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Matt
Matt
7 months ago

Thanks for all you help. I’m happy with all the products you recommended and how it turned out

CJO
CJO
7 months ago

We have a deck constructed with Trex or similar, but the railings and posts are an exotic wood (IPE?) and the finish has faded over about 6 years. Not sure what was on them previously. Recommendations to refinish the railings-stain vs. urethane vs something else?

Jane Stewart
Jane Stewart
7 months ago

Im going to stain my deck that has been sanded.Should i put thompsons water seal over it when its dry

Joshua
Joshua
7 months ago

What about a spar urethane with regular maintenance? Was thinking along the lines of 1-2 re-coats a season. I know it’s softer, but was curious about speed of wear. My deck isn’t a typical gathering place.

Andree
Andree
8 months ago

I gave my deck three coats of glossy stain and now there are always white water marks on it

Jeff
Jeff
8 months ago

I just put a coat of stain and sealant in one and it was the wrong color I need to know if I can us the same product just a different color on top of it or will it not stick

Pam Dennison
Pam Dennison
7 months ago

What if it Behr Semi-transparent stain and seale?!…. Behr says I can but second coat of stain not penetrating which we know it is a sealer so how could it?? Not using Behr on main deck what should I use? It gets a lot of shade therefore I’m thinking it will get mossy then too therefore I went with the water based Behr.

Tammy Johnson
Tammy Johnson
8 months ago

I have an interior stain that I would like to use on our porch floor and deck. Can I seal it with a clear seal coat for decks.

Jerry B
Jerry B
8 months ago

I have power washed my deck then sanded then applied Cabot deck stain do I now need to put a clear sealer on it or not?

Jerry B
Jerry B
8 months ago

Why is that?

Ronnie
Ronnie
8 months ago

I have a cedar gazebo that needs some TLC, I stained raw cedar with Sekins Log and siding cedar stain color , I’m going to clean and redcoat, it been about 6 years since It was done, any suggestions for this project for longevity

Ron Kinnison
Ron Kinnison
8 months ago

Can polyurethane be painted over MgO for added protection

Jessica Hinojosa
Jessica Hinojosa
8 months ago

Hi. I am about to stain and seal my new deck (new treated pine wood and has never has been stained or sealed) and want to know if I can use two different colors of stain + sealer. I want to have dark highlights on the flooring. I’ll attach a pic of what I am trying to achieve. Is it possible to use two different colored stain + sealers to do this or should i use another technique or product? Basically how can i get my deck to look similiar to the pic? I have tried to look up DIY tutorials and haven’t had any luck. Thanks!

Jessica Hinojosa
Jessica Hinojosa
8 months ago

I attached a pic.

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Jessica Hinojosa
Jessica Hinojosa
8 months ago

Thanks for the quick reply and for the info. .. So are all milticolored wood deck flooring IPE then? For example this pic attached doesnt look like IPE to me. It looksnasnif someone stained the wood to get that effect. I was originally going to do the picture frame edge I have in a darker color as suggested but was hoping I could blend in some of the darker color into the flooring as well. But I seriously do not want to make a mess of it and have to redo anything. As per my previous post, can you layer over a lighter colored semitransparent stain and seal with a darker colored one to create that kind of effect? Or will that cause peeling or other problems? Thanks again.

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Jessica Hinojosa
Jessica Hinojosa
8 months ago

Ok thank you for your help.

Aaron
Aaron
8 months ago

I built a patio sofa out of reclaimed 2″ x 4″s. My wife likes a stain only available in an inside stain. Is there any way to stain it with interior stain and still put a water seal, such as Thompson’s, over it?

Kristen
Kristen
9 months ago

We had cedar posts built for our front porch out of rough cut cedar .. the co tractor told me to seal them.. at the time I just used a water based transparent sealer about a year ago .. I now would like the cedar posts to be darker and would like to use a semi transparent stain by Sherwin Williams in chestnut ..can I do this? Do I need to pressure wash first and sand the posts? And then apply the new semi transparent stain ?

Kim Simons
Kim Simons
9 months ago

I just bought two Adrionick chairs for my back deck. I stained them with Cabot. I ordered a lifetime wood preserver. After reading some of your comments, I’m wondering if I should apply the lifetime preserver over the stain or just leave it like it is.

Sandy Boyle
Sandy Boyle
9 months ago

Used valspar one coat stain last fall. Deck has lots of white water marks and looks dry. Can I oil the deck this year over the valspar stain from last year to refresh it? What product can I use?

Martha W.
Martha W.
9 months ago

Is it ever appropriate to use an exterior linseed oil/ alkaloid based weather resistance deck stain on a historic small space wood floor? Are there chemicals in the exterior stain that prohibit application to interior floors, even if all precautions are taken during application and drying. Thank you.

Lori Murphy
Lori Murphy
9 months ago

We built a pool deck last spring with pressure treated lumber and stained with Thomson’s water seal in Sept 2020. We put no furniture back on the deck. We went up on the deck about a month ago and it looked like it had been stained five years ago. It’s peeling up and chipping off. The deck gets full sun, wind, rain, snow and whatever else Mother Nature throws at us. What will be best to repair this and hopefully make the stain stick and hopefully last longer than a few months. I’m not looking for an easy way out, just the best method and stain. Thank you!

Jim
Jim
10 months ago

Made the mistake of using Valspar’s “one coat clear exterior sealer”. My boards are now a disgusting yellow tint. Have any ideas of a stain or product I can put right over the top to at least darken it into a tan or brown? I am not up for stripping it at this point. Thanks for any ideas you might have.

Juliana Jordan
Juliana Jordan
8 months ago
Reply to  Jim

Gel Stain may work if your Valspar was polyurethane base and you’ll have to refresh yearly. Here is a link I found. Gel stain doesn’t work with varnish, lacquer or shellac — only polyurethaneIf it’s an older finish, test it to make sure it’s polyurethane. … If it sticks to the finish it’s varnish, shellac or lacquer, and you can‘t use gel stain on it.

Can You Stain Wood After Polyurethane Has Been Applied …

Tom Gibdon
Tom Gibdon
10 months ago

My deck has been painted but needs to be repainted this spring. Steps and entry ways to the deck that have been exposed to weather and sun need to be sanded to bare wood. One contractor wants to sand the entire deck to bare wood. Repaint with two coats and optionally add a clear coat. While other contractors only want to sand weather worn areas then paint and no clear coat. There is a significant price difference. Which would you recommend? Full strip or only areas needed?

Annie
Annie
10 months ago

I have used a Cabot’s polyerthane matt finish and I am unhappy with it on the shiplap cladding at my house
Can I sand it back slightly with a 160 grit and then use a natural decking oil?

Andrea Foust
Andrea Foust
1 year ago

We recently built a shop and used decking materials on the INSIDE railing and staircase . I used deck stain for the durability ( work boots ,etc) I would like to use water-based poly over the water-based decking stain to repel the dust that shows so bad on the stair treads. Can see every footprint. Would it peel even though its not outside in the sunlight?

We live in South Carolina and have an unfinished w
We live in South Carolina and have an unfinished w
1 year ago

We live in South Carolina and have an unstained wood deck. There is no space between the planks, which causes the water water from rain to collect there. In our heat and humidity, this almost immediately creates green mold. Also, on other parts of the deck, even if I have my planters on trivets, green mold and mildew will appear within a week or two of cleaning. What is the best thing for us to do to improve the situation? We are willing to start from scratch.

We live in South Carolina and have an unfinished wood deck. There is no space between the planks. As a result of this, water collects in the grooves and turns green quickly. Green spaces also appear where I have plants on the deck, even if the plants are standing on trivets. There’s been so much water accumulating on the deck that many places at the edge of rotted. What do you recommend we do? We are willing to start from scratch.Thank you so much for your unbiased responses. We really appreciate it

Al C
Al C
1 year ago

I applied Behr semi transparent stain and sealer to a bare wood deck. Is there any “other” treatment I could do for water protection and longevity?

Dennis A Bigley
Dennis A Bigley
1 year ago

I have a deck with two coats of Pittsburgh Paints slolid stain. The leaves that fall are staining the deck. What can I do to prevent this?

James
James
1 year ago

So if I want a deck stain with water proof characteristics, would I just pick one that’s both a stain and sealer?

Cynthia N
Cynthia N
1 year ago

I have a dog how long should you wait before allowing them to go outside?I just stained my fence ?

Cynthia N
Cynthia N
1 year ago

Thank you for the super fast response.

Justin
Justin
1 year ago

Hi. HELP. I’m in the process of building a deck and will be using older lumber for 2/3rds of the job. I’ve seen pictures of some nice decks that look like they have a clear coat. I read you can’t stain then put clear coat but can i put a poly finish/ stain mix? The new lumber is pressure treated so do the same🤷🏻‍♂️? Thanks

Linda miller
Linda miller
1 year ago

I used light gray paint on my deck with the granules in it for non slip. It gets so dirty and is very hard to clean. Any suggestions ??

Steven
Steven
1 year ago

Used redwood stain on my porch swing. Do I need to seal it and with what. It is exposed to all weather.

John Cole
John Cole
1 year ago

Can I put clear coat on if I stain it till what or do I have to let the stain dry before I clear coat

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