Question For Woodworkers

[projectnut]

One of the projects for this winter is making new decking for the pier at the family cottage. This will be the second time around for new decking. The originals lasted less than 10 years. The first replacement set I made lasted 13 years. In both cases the ends of the deck boards are deteriorating to the point that they have become soft. They will probably last another year, but I don't want to take the chance that one or more might break and injure someone.

The new decking will be made of 5/4" x 6" cedar just like the originals and first set of replacements. In the past the end grain was sealed using a couple coats of brush on sealant. This time I'm considering soaking the end grain in sealer for a period of time to get better penetration, and hopefully longer life. When completed all the boards will get two coats of sealer top and bottom. Other than that, they will be left to weather naturally. In all there will be about a hundred deck boards and an as of yet to be determined number of stringers.

The number of stringers is dependent on whether the sections are 2' or 4' long. In the past each metal framework had two four-foot sections and one two-foot section of decking. We've yet to determine whether we want to duplicate this pattern one more time or go to two-foot sections only. The upside of two-foot sections is that they are easier to install and remove. The downside is they're more prone to displacement due to wind and waves.

My question is: Is soaking the end grain a viable way to attempt to reduce deterioration, and if so, what sealant is best for this application, and how long should the boards be soaked to get maximum penetration?

 

[RJSakowski]

If it were me, I would be considering one of the composite decking materials. I used a polyethylene infused product in my boat twenty years ago precisely because I was concerned with rot in a wet environment. It shows no sign of deterioration to date. It is lacking in esthetics but form follows function.

 

[projectnut]

If it were me, I would be considering one of the composite decking materials. I used a polyethylene infused product in my boat twenty years ago precisely because I was concerned with rot in a wet environment. It shows no sign of deterioration to date. It is lacking in esthetics but form follows function.

We took a vote on what type of material to use. It was 1 vote for cedar, and 1 vote for composite. I lost, so cedar it is.

 

[Eddyde]

I agree with RJ, composite decking, rated for dock building is the best way to go. However, I understand there may be greater forces at play...
What material will the cedar deck boards be fastened to, the framing?

 

[Eddyde]

The sealer may be helping to cause the rot. Sealer is usually used on the ends of deck boards to keep them from drying out and checking/splitting, by sealing you may be helping them to retain moisture. Can you post pictures of the existing pier?

 

[projectnut]

The sealer may be helping to cause the rot. Sealer is usually used on the ends of deck boards to keep them from drying out and checking/splitting, by sealing you may be helping them to retain moisture. Can you post pictures of the existing pier?

I agree with RJ, composite decking, rated for dock building is the best way to go. However, I understand there may be greater forces at play...
What material will the cedar deck boards be fastened to, the framing?

The sections are not physically fastened to the aluminum frame. They sit inside the frame. They can be placed in any order as long as there are two 4-foot sections and one 2-foot section in each of the longer frames. The shorter frame has a single 4-foot section. Here are a couple pictures of the pier from 2017 when the pontoon boat was being delivered for the summer season. The pier has been extended since then, but the new sections are identical to those in the pictures.

 

[woodchucker]

I'm in Ed's camp. Sealing is a bad thing. It doesn't let it dry. Latex paint is also bad... it creates a rubber seal and just allows the wood to sit in the water

 

[Larry$]

Another vote for composite. No idea about the sealer. Just don't use any wood that shows sapwood, it's not rot resistant.

 

[projectnut]

I forgot to mention this entire pier is taken out each fall and put back in for the summer months. We tried a permanent structure back in the 1980's. The ice wiped it out in one winter. It took most of the following summer to pull out the broken pilings. Since then it's been a temporary structure, in every spring, out every fall. The wood pieces are set on their sides and covered with plastic for the winter and the frames are set along the shoreline.

 

[Eddyde]

The captive frame will hold moisture on the ends of the boards, I would definitely omit the sealer. Teak or Ipe decking would be another natural alternative and more rot resistant than Cedar, Black Locust would be another worthy candidate.