Restain a 3.5 year old deck - Do I need to strip?
I built a fairly simple one story deck three and a half years ago and used Behr 2 yr transparent stain/seal.
Do I need to strip it down, or could I just go ahead and restain it (and this time with a 6 year semi-transparent stain!)? Gave it a light power washing the other day to clean it off.
Live in Austin, Texas -- very hot!
This is a perennial question and this discussion really opens up a lot of other questions because there are various types of stains and sealers.
Most stains now are acrylic. Very few are oil based which tend to last longest. Sealers are a different product all together.
So I am going to share with you and our visitors some personal experience working with a Behr 2-year stain. Note that I am referring to their stain, not specifically a sealer. So this may be slightly off point but many of the lessons are transferable.
Acrylics may be very convenient to wash off and clean up afterwards but my experience is they compromise on performance in a significant way.
The 2-year Behr product never lasts two years. It's an annual rite of tradition to clean, even sand down areas where its peeling and re-apply.Re-Applying
In order to have any chance of these products working in the first instance, you must apply a very very thin coat. Resist going for the once over white wash technique.
It may look a bit darker, give you a bit more color, but it will most certainly not adhere properly to the wood.
This will be further compounded by sun and hot temperatures during the application. If you are in Austin you are talking about severe summer heat.
Applying this kind of product means waiting until there is probably some cloud cover - certainly no direct sunshine - and temperatures of 65-70F (17-20C). You will regret it if you do not follow this.
I have learned over and over and over again using the acrylic stains and sealers to follow this rule.Manufacturer's Claims
I often wonder what is the basis for claiming a deck stain will last six years. Where did they test it? There are some places in North America with summers over 100F and winters down to 0 to 10F. That is extreme.
Six years? Really? Ok, maybe but I take that like a grain of salt.
Sealers are designed to function a bit differently in that they should be providing a physical barrier to water. Thompson's water seal is one that comes to mind.
However, sealers have other challenges to over come. They do not have to impart color but they must create a barrier. And they must handle foot traffic. Two double whammys.
No way is a 2-year "sealer" going to ever last more than 2 years and I would honestly say one year is all you should ever expect.
There is one on the market now that is showing some promise and is originates from Australia where they have sunshine and temperatures even higher than Texas. It is called Cutek. I would check this out.
Stripping The Deck?
Truthfully, if you want a sealer to do the job properly and if it was acrylic you should strip it off. Otherwise you are layering more on top of some areas which are barely adhered to the decking anyway.
The reason I like what I have seen so far with Cutek is that is penetrates deep into the wood like an oil - I belive it may indeed be partially made of oils - and it seems to last a long time.
Here is my deck after a tough winter.
And then after sanding - but not stripping completely - but applying a very thin second coat of Behr 2-year semi-transparent acrylic deck stain. It still doesn't look great because the deck was not completely stripped. But the second coat has withstood the following winter.
Other Professionals - Please Share Your Experience
I have just shared my personal experience and it is limited but it is real. I know there are lots of very seasoned builders and contractors in different parts of the country who are steeped in experience.
Tell us what you have found and help our visitor out.