This post was updated on March 1, 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.
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.
Deck Stain Help & Questions
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As an article and comment contributor to the site, Scott has been around the pressure washing industry since attending college. In 1993 he started his first company called Oakland Pressure Wash specializing in exterior pressure washing and deck staining. That company evolved into OPW L.L.C. shortly thereafter concentrating more on exterior wood and deck restoration. Scott and his Deck Cleaning Michigan company have restored over 10,000 decks in the Metro Detroit area since the early years. He has become an authority in the deck restoration industry and has contributed to numerous wood restoration forums and informative sites.
All the products he suggests through this site are sold through online sites and in retail stores, allowing the consumer to choose their own means of purchase. Scott’s eCommerce sites do sell many top brands he endorses and if you appreciate any of the help he has offered then feel free to purchase from one of them.
can you mix clear olympic summit stain with olympic summit mahogany blaze and will it adhear
Sorry but no idea. We do not use the Olympic brands.
Scott, My deck was re-stained about 4 years ago and needs to be done again now. However, I love the weathered look of it as it is. Can I put a clear finish on it like it is to protect the wood and keep the look?
The stain that’s on it is an acrylic PPG product called Flood pro series. What do you think?
No, you cannot Clear sealer over a deck stain and you cannot apply a Clear sealer over weathered wood.
Hello Scott, Our deck is 20 yrs old, made of Pau lope wood. It is grey and weathered. Last year my husband had it power washed, it looked nice for a few months. We have only lived here 4 yrs so I don’t know what was done prior. Please help there isn’t anyone in our area that does this sort of restoration. My first question 1.) Is “Restore A Deck” the best product for us? 2.) Do I need to clean the Pau lope decking before applying (power wash?; to get off some black stains on railing?) ? I really believe this deck could be beautiful with the right help.
2. Use a deck cleaner while pressure washing for prep.
Hi. I have a redwood table and benches that I refinished, sanding and applying a semi transparent stain. I read your really helpful article on putting sealer’s over stained wood, so I won’t be doing that. But is there anything else that can be applied to keep the waterproof protection? Ting or teak oil maybe?
No, you cannot apply anything coating over a deck stain.
Hi Scott, my 13 year old deck is in rough shape. Earlier this year I cleaned it thoroughly, repaired rotted areas and then applied Behr’s deck paint. It looks good but I noticed that water is not beading up on the deck. I’ve read your article and scrolled through these questions so it would appear that sealers are not an option. Any recommendations? Thank you.
Leave it alone. It is misinformation that deck stains are supposed to bead water. They are not.
We just wrote an article on the subject for you:
Hi Scott can I put a finish like poly, over semi transparent stain on a dresser?
Interior wood is completely different so best to use interior stains and poly coatings for a dresser.
Scott, thank you for your sharing your expertise. I am building a new deck. I like a glossy/satin look showing the depth of the natural wood grain and color. I am overwhelmed by how much information there is on the subject. What product and process would you personally use if this was your main objective?
Never put a gloss coating on a deck surface. It will peel and blister, making removal when it fails very difficult.
See here about new wood: https://www.deckstainhelp.com/how-long-should-you-wait-to-stain-a-new-deck/
I have installed composite deck 5 yrs ago.It changed color lit a bit,can I use wood stain
to refresh it
If it is porous, then yes.
Hi I painted my inside stairs with solid pain no stean last night. Now I want to ask you I need use polyurethane after solid pain? I checked stairs they are dried but no 100 % may 70% it still steacky .If I need how long I need to wait to applay polyurethane
Thank you .
No, it will peel if you apply a poly over paint.
My Tompson wood sealer turned white when I tested it on a part of my deck,could you please tell my why and what I can do to fix it?
Thompsons is a useless product and does not work well or at all. You will need to remove it to fix it. Strip and brighten the wood.
Can you apply a clear coat over a semi transparent wood deck oil based sealer?
No. It will peel.
Hi there – I have one board on my deck that gets more rain than any other, it gets worn down every winter, and I recently re-stained it. I thought some sort of extra thick poly on that ONE BOARD would be helpful. I guess I could put 5 coats of stain on it. Any ideas?
No, you cannot do anything to make that one board last longer. 5 coats of stain will not work and make it prematurely fail as more stain is not better.
Thanks Scott! I’m going to try a gutter solution on my overhang that pours all the water on the deck, stopping the problem before it gets to that board. Your input has stopped me from trying 2 bad options – much appreciated! Thank You!
We have removed 5 layers of old pain and sanded the front porch. We stained it in red mahogany and it looks very nice. The porch is covered and not exposed to much sun during the day, but it gets wet during the rainy days. Would you be kind to recommend the clear protective coat we could use. Thank you!
You cannot top coat over a deck stain with a sealer. Please read the article that explains this.
Hi Paul, I have an IPA deck and walkway. 8 years ago it was completely sanded on both sides and flipped. Duckback Superdeck Waterborne IPA formula was applied… then a few years later, again Deckback Superdeck Waterborne IPA formula was applied after light sanding… a couple months ago very light sanding and then Armstrong Clark Hardwood Oil based formula was applied. Already the oil based formula is spotting and losing all of its color. Do you have any suggestions of what I can do and what product to use? Thank you!
Try Restore A Deck Stain in Light Walnut. Strip off the current stains first and then brighten:
Hello, I purchased a Cedar Pergola kit from Backyard discovery through Lowes Hardware. The unit came with a waterborne “translucent stain for color only”. They also say as part of the warranty that I need to apply some sort of protection. Can you recommend something? I was thinking a clear sealer but there are a lot of posts and blogs that recommend that you should not do this over a stain. I really don’t know how to solve this.
You cannot apply a clear sealer over a stain. It will peel if you do. You will have to remove the current stain and then apply a proper wood/deck stain.
Thank you for reply Scott. You’ve reconfirmed what I’ve been learning. This makes me wonder why Backyard Discovery Would sell a pre stained product and then tell you that you need to put protection on it as part of the warranty. I will certainly be asking them.
They are passing the buck in case there are issues. They are clueless to the fact you cannot top coat over an exterior wood stain.
After consulting with staff at a Sherwin Williams, I used Superdeck Exterior Deck Stain Waterborne on an interior stairway application. Given it will not be exposed to the elements, can I safely use a water base polyurethane to create a semi-gloss protective surface. If that is possible how long of a cure does the Superdeck need before Polyurethane is applied. Yes, I do a lot of non traditional and sometimes stupid things.
No, you cannot use poly on outside wood. It will peel.
I read your other responses first and understand that poly can’t be used on outside wood. As I noted in my question, the area I used the stain on is an internal staircase that is not exposed to the elements, only human feet and cat paws. I was more concerned about any chemical issue caused by adding a poly top coat, having had an issue some 30 years ago in a theatrical application where an oil top coat was used over a water based paint.
Sorry. Not sure if a poly will or will not work over an exterior stain on an interior wood case. We have never tried it.
Running a test patch today, will let you know. The stain did a great job making some very old and marred treads, buried under carpet for 40+ years look great.
For the record, test patch went fine. First coat looks great, three more to go for this non traditional use of Superdeck Exterior Deck Stain Waterborne for interior use.
Are you supercell 30 on my fresh concrete, in a process of building it’s got dirty and scratched up would like to change the color any advice thank you
This is a wood and deck stain site, not a concrete site.
Hi. I just put down Sherwin Williams Super Deck Exterior Stain, Waterborne Formula, in Flat Finish on my deck (in the color Iron Ore). Can I apply spar urethane over the Super Deck Exterior Stain, or is it unnecessary and/or harmful to the Super Deck Exterior Stain? Thank you.
No, you can never top coat over a deck stain with a poly or a sealer.
Hello I just purchased a cedar pergulas,
It is stained but not sealed, I would like to polyurethane it so I don’t have to use a sealer every other year.
What are your thoughts
You cannot do this. It will peel if you do.
If I apply this over my painted deck will protect it from foot prints and shoe prints
No. Please read the article. You cannot apply a sealer or poly over paint.
Can you apply 100 % acryic deck stain over spar varnish ?
No, it would peel. You will have to sand off the spar varnish.
Hi Scott – question about our deck – I wash and restain about every other year. My problem is that I forgot what product I used the last time around!!! We live at 9000’ in Colorado so the sun really does a number on the wood. Under our porches I thought it had just not been sun damaged as much as the fully exposed areas so I applied what I thought was the right product but I am pretty sure it is the wrong one. I think I have Behr Waterproofing Wood Finish and I went over it with Woodguard exterior wood preservative (oil based) which is for our logs.
Can I just let this all sit and hopefully dry and then wash/strip next season or will the oil just never absorb and I have to address now?
Thanks so much in advance !!
Most likely it will not cure and dry correctly.
Thinking of using a decking paint instead of decking oil. After reading reviews on decking paint, quite a few have mentioned 12 months after applying, peeling as appeared. So my question is can I use a clear sealer on the decking paint to prolonged it’s life…
No, you cannot apply a clear sealer over a paint.
Okay thanks for your quick response.
We had a new redwood deck installed 4 years ago and stained it with PPG ProLuxe SRD RE wood finish. The stain has held up well, but dirt and grime has built up on the surface. I intend to reapply the same stain this year. My question is should I strip the old stain and brighten the wood before re-staining, or can I simply clean and then reapply the stain?
Post some pics in the comments.
The photos are typical of the condition of the deck. Thanks for taking a look.
Clean and recoat should work if using the same exact stain and colot.
Thanks Scott. I recently discovered your website and have marked it as my go to for information on deck/siding maintenance.
You are welcome!
i am using Behr waterproof opaque stain & sealer on an INDOOR new pi e wood floor.
the staining has led to the wood grain expanding so the surface is now quite rough.
Because i think this will make it hard to keep clean, I want to apply some sort of final clear coating. I was going to use pony but then read your posts!!
Do you have any other ideas?
No, you cannot top coat it, it will peel.
This is not a deck question but… I am making a table top for an outdoor patio table. I am purchasing a high end piece of “plywood”. Having it cut to size. I’m going to sand it down, place Varathon interior wood stain, Weathered gray then I would like to seal it with a marine varnish. Will this work?
It will peel if exposed to the elements.
It will be somewhat protected from the elements. What do you recommend I do instead?
No filming coating like poly or varnish will work on outside wood. Also, your Varathane stain has zero UV protection for the outside.
You need a penetrating wood stain with UV protecion: https://www.deckstainhelp.com/the-5-best-deck-stain-reviews-and-ratings/
Good morning, I applied the newer Behr advanced deck over smooth to my additions plywood floor and it looks great, my question is because there is still some roughness to the finish not because of the plywood it has a tendency to scuff which isn’t permanent but unsightly and a housekeeping issue. My question is can you apply floor wax over it as I don’t want to spend the time or money using a poly.if that was the case I could have painted it for less money.
You cannot apply floor wax over a deck stain or deck resurface coating. You cannot put anything over the top of the Behr Deck Over.
Thanks, guess will have to wear socks.
We applied Valspar One-coat exterior sealer Clear on our new deck. We were told to use a sprayer for application. The finish turned out horribly. It has bubbles and the finish still feels “sticky”. Now we have one half of our wonderful deck with this mess. The other half has been untouched with the product.
How do we remove this sealer and start over?
Most likley need to sand it to remove it.
Thank you for your help.
You are welcome!
We asked a company to stain our swing set. They power washed then applied stain. They used Varathane interior stain (English Chestnut). It rained two hours later after the wind blew pollen onto the still wet stain. After drying for a few days it still feels sticky. They’re applying more stain today to even out the color. I called Menard’s about sealant and they recommended this and that but then I found this site saying we shouldn’t do that. Help! What should we do to make the best of this disaster? Thanks for any advice.
There are using all the wrong products and adding more will make it worse. The only way to fix is to remove all and that will require power sanding.
I have a mahogany deck about 7 years old. Every year I clean it with 30 second cleaner then seal with Penofin transparent oil finish. Within a month the wood has darkened each time. I live on the coast with full sun and high winds. The wood has never looked like it did when new. I would like to use the Restore a deck water cleaner and water based semi transparent. Do I have to strip this first? It has been a year since I applied the Penofin.
The issue is Penofin has known issues with turning black: https://www.deckstainhelp.com/penofin-exotic-wood-stain-review/
You do need to strip and brighten for prep. The only good thing about Penofin, is that it is easily strippable. Use the RAD Stripper/Brightener Kit for prep and then the RAD stain in Light Walnut
Thanks for the prompt answer. Why would I want to put a color stain on the deck and not keep natural?
Clear (no color) offers zero UV protection from graying. It must be tinted for UV protection. Penofin was tinted as well.
I’m a confused newbie. I’ve done hours of research for this planter (first photo) that I just purchased.
According to many reviews, if some kind of protection is not applied it will look like photo 3 within a few months. Some reviewers have advise water seal or poly with shine to give it a beautiful shine.
After reading your many responses here, my plan is all shut to hell. I had bought on the advise of L*wes worker, Valspar semi transparent Stain and water seal Sunlit copper to give it a reddish tone.
And I was planning on mixing this with Spar varnish to give the Valspar flat color stain some shine in it. Dirt rolls off better off of smooth shiny surfaces than flat coarse like feeling ones.
But you say that these products don’t mix and will peel. What can I use to achieve my goal?
Below is the wishing well description and photos of reviewers.
Thanks in advance for your help.
The planter made of solid wood has a heavy texture, durable and firm. The surface of the board is smooth, after many times of shaping and grinding, the texture is clear, and the corrosion resistance is durable for a longer time. The surface undergoes high-temperature carbonization treatment.
Fir wood is more secure
Carbonized at high temperature
Rural retro style
Durable and firm
Material: fir wood
Color: carbonized color
It is already stained. Leaver as is until time to redo in 1-2 years. Use a penetrating stain when time to redo. Never apply poly to exterior wood.
I have a new deck made of pressure treated pine deck boards. its now 5 months old and ready to seal it or waterproof it. I want to protect it but I want a natural look, no color. Even like the graying as it gets weathered. what product do you suggest we use?
Defy Extreme Clear or TWP 1500 Series in clear. Both have no color but will protect while graying naturally.
I used Cabot semi-transparent stain and sealer on new wood deck on my trailer. I have let it dry for 48 hours. The instructions say to only use one coat. Would two coats be better, or not?
This is not a question regarding a deck, but thought I would post anyway. We are installing a pine tongue and groove ceiling in our newly built outdoor patio. We already applied Behr Premium transparent waterproofing wood finish in cordova brown (mainly used for fencing, decks, etc…. We really like the color but my husband feels we should now finish it with an outdoor polyurethane. Again, this is a ceiling in an outdoor patio and will be completely protected from rain/water/snow. We are wondering if adding polyurethane is necessary to protect the ceiling from moisture? We live in Michigan so summers are humid and winters are cold. Thank you in advance for any helpful information as we have not been able to find any answers on our question.
Do not put a poly over it. It will peel and attract mildew and the Behr cannot be top coated.
Ok, thank you very much. We will leave it as is and hope for the best!
Hi. I used Ronseal Decking Rescue Paint several years ago. Every year parts of it flake off and needs repainting. Can I buy a product to paint over it to protect it? Some kind of heavy duty varnish? Thank yo.
No, you cannot top coat it with a varnish. It will peel.
My solid deck stain is peeling and due to plants, patio underneath and fish ponds, I can not do a chemical strip. I have been sanding and like the eorn look( kind of like in your photo). Is there anything I could use over the wood and stain. Clear or a very light transparent stain ? Others suggested Spar varnish but…….
No, you cannot topcoat over a solid stain with a sealer, light stain, or varnish. You can recoat over the intact solid stain with another solid stain as long as all failing/peeling stain is removed first.
Can I use Cabot semi transparent stain and sealer in bedroom?
No you cannot.
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.
If a true clear sealer (with no color or pigment at all) then it will not provide UV protection from graying. Many times stain companies will call a product “clear” when in fact it is not clear but lightly tinted. Basically, if it enhances the natural grain of the wood at all then it is not a true clear and then it will also provide some UV protection since it has pigment.
One caveat on this would be Defy Extreme Clear. It is a true clear with no pigment but it has some nanoparticles of zinc oxide (a white pigment that is invisible to the naked eye) in it that will give a small amount of UV protection. Probably lasts 9-12 months on a deck at most before it starts to gray.
Zinc oxide is the same thing that is in sunscreen. It just does not last very long on a horizontal deck.
I applied deck stain to handmade bed. Can I use a paste wax to give it a more finished look
No. You cannot top coat it.
We stained our old deck with semi solid deck stain with sealant. Can we apply water sealant on top of it for extra protection?
No, you cannot ever apply a sealer over a deck stain.
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?
You cannot top coat it. It will peel.
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.
You cannot add a clear coat or poly over it. It will peel and fail eventually.
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
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.
No need to use the preserver. Just use the stain and then you are done.
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.
Sorry, I suppose the answer is in the fact that the stain is for “exterior” use. I guess that
Hi, I stained my house and I used the stain to do my breezeway deck can I apply a sealant to protect it?
No, you cannot apply a sealer over a deck or exterior wood stain.
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
Post some pictures of your prep.
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?
Use Restore A Deck Stain in Natural or Armstrong Clark in Amber color. Never apply a sealer over a deck stain.
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?
No. There is nothing you can add on top to prevent dirt and there is not an easy way to clean off the dirt besides soap and some scrubbing.
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.
No, you can never apply a sealer over a deck stain.
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?
Strip off the Thompsons and then use a stain like TWP in Honeytone color or Restore A Deck Stain in Natural tint for a wet look.
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.
No, it will peel if you do this as the above article explains. You need a penetrating stain instead.
What would you recommend for a protectant then? I do not want to stain it, I only want to protect it from the elements.
It will gray in months if you do not have a stain. Are you okay with this?