Post Anchor Mounted On Composite Decking

by Christopher
(Maine)

Can the titan post anchor be used on-top of composite deck boards the same way it is installed on wood decking? I will be installing a Timbertech deck and would like to know if the post anchors can side directly on the composite deck with the anchor bolts penetrating through the composite deck to the joists and added support structure underneath to pick up the anchor points.

Editor Comments

With hardwood decking, you're going to have to pre-drill. What you wanna do is pre-drill either a complete hole through that top deck board and then allowing the threads to pass through without contacting the wood and then straight into the blocking below.

Check out this video for more information:

Video Recap

Hey, just received an email from Mike and Mike is asking today how to use the Titan Post Anchor, how to secure that onto a deck when the decking is a Brazilian hardwood. You're probably familiar with these hardwoods, they go by names like Cumaru, Ipe, Tigerwood, Kayu. There's a bunch and one thing that's very characteristic of them is it is that they are incredibly dense. They are so dense that sometimes they don't even float, they really are like nature's steel. And so the question is "If you use brazilian hardwood over a regular common softwood frame substructure how do you screw into that? How do you secure the base of the anchor through those deck boards and is it a little different than when you're on a treated pine or a cedar deck?" And the answer is yes.

With softwood, you can drill right through, with hardwood decking, you really have to pre-drill. What you wanna do is you wanna pre-drill either a complete hole through that top deck board and then allowing the threads to pass through without contacting the wood and then straight into the blocking below. And you don't need to drill into that block but you do want the screw to bite. So, you would drill through the first deck board and that's it. And then you could take the screw and it could go straight into the blocking.

But yes, you do need to go through the decking and you do need to get into some of that blocking blow. If you rely on these deck screws, just on that five-quarter deck board or, in some cases, only one inch, what you're doing then is you're assuming that the deck board is secured to the joists and can never budge. And maybe, maybe not, but what we'd like to recommend is that you put the blocking between the joist bay, you go through that deck board and into the blocking. If you follow that, you'll have no problems.

One last thing, I probably recommend that you take both a seven-thirty-seconds inch drill and also a fifteen-sixty-fourths which is ever so slightly larger in diameter and play with it on a scrap piece just to see what kind of torque and resistance you're getting with the screws because remember, these are manufactured, but they're not manufactured to within one thousandth of an inch accuracy. There's some variance. And with hardwoods, that little variance can really make a big difference. So, you're working with really tight tolerance on your drill bit and then you play with the variable size of the screw to get that right size. Follow that, you'll have no problems. Good luck.