Securing 6ft 4x4 poles to my deck

Hi all,

In a recent thread I mentioned I'm planning to build a privacy wall at the end of my deck. My plan is to create a wall using 4 - (6ft 4x4 poles) that are roughly 5ft apart - this will cover the entire end. Then, I am going to install Pylex sunblind hardware that will allow me to connect 8 1x6 boards in between them all - the overall picture should look like this:



My current deck uses 2x10 board joists that makes up the frame and the top is using 1x6 boards. I plan on using Titan 4x4 anchors for each of the 4x4 posts, and before I install them, I plan to support the sections under the 4x4 posts using a block of the 4x4, i.e. 3 inches attached to the side 2x10 joist. Or could I just use a section of a 2x4 instead of having to cut a 4x4? The image below shows the outside 2x10 joist I would secure the support to - I'm really wanting to know what best support I should have here to secure the Titan anchor:


I will then install a new 1x6 board on top of that area and secure the Titan anchor to the section. I will do the same to all 4 sections where I plan to install the 4x4 post.

Do you think this will be enough support to hold the 6ft 4x4 posts?

Thanks all. Please note I will be replacing all rotten wood with new boards.

This is what the section of the deck looks like:




Rob

 

IMO you would want to add some perpendicular 2x10 blocking between those 2 joists. Tack the 4x4 temporarily to the rim joist with a few screws to hold it in place, shim it as needed to plumb it. (Don't assume it's plumb and aligned with the other posts just by bolting it to the rim.) After you plumb each post, sandwich each 4x4 between 2 pieces of perpendicular blocking with 1/2" bolts that are parallel to the rim joist. Then add a 3rd bolt through the rim joist and post.

And by the way, you will be better off if you center your posts on the seam between 2 planks... not centered on an individual plank. That way you will just notch the two planks to fit around each post. If you center it on a plank, you have to cut a perfect 3 1/2 x 3 1/2 hole in a plank and slip it down over the top of each post, which is NOT a good plan.

 

Thanks XSleeper. Just to confirm, I'm planning on securing the 4x4 post to a Titan 4x4 anchor. The anchor is going to mount to the support I'll create between the joists. In your instructions above, are you referring to securing the post down into the joist and support blocking?

Thanks,
Rob

 

Yes, I was referring to bolting the post down into the existing framing and to the blocking you would need to add. I would not use the titan anchor, especially not for a 6 ft fence.

 

Aren't those anchors only recommended for short posts like 36" max? I would consider using longer posts and extend them through the decking to attach to the framework below instead of trying to surface mount them on top of the deck boards.

 

Thanks again for the response. This is an actual look at the 4x4 in between the joists. It looks like there won't be room for a 2x10, as the support wedge I used is from a 5/4x6. But is the idea to put bolts from the outside rim joist all the way through to the inner joist?

 

Thanks Pilot Dane, I'm going to rule out the Titan anchor and connect the post into the framing. I'm trying to find out the best way to do this now.

 

Your picture in post 6 is not what I was suggesting.

In post 2, I suggested installing blocking perpendicular to your rim joist. You would cut two pieces of 2x10 to the right length to go on each side of the joists. Your post would fit in between the 2 joists that are pictured in your 2nd photo in post 1. Looks like they would be about 4 1/2" long. The tighter they fit the better. Pound them in from the top without splitting them. Then plumb the post and fasten everything together, with bolts... and fasten the perpendicular blocking to the two adjacent joists.

So your post would be surrounded by wood on 3 sides. The spot where you have the deck block wedged in would be left open... it is where your open end wrench and the nut would go for your rim joist bolts. And you'd have 2 other bolts going through the 2x10 blocking you added. As for the gap you put the decking block in, you "could" fill it with a wood shim like you pictured in post 6, but you would need longer bolts to go through the rim.

If you have a table saw, you could rip just the right size shim to hammer down into that gap, as you show in post #6.

 

This is helping, thanks XSleeper, and sorry for these newbie questions. I'm not sure if I still fully understand your explanation, but I feel I'm getting closer. Based on your explanation, I'm picturing the following diagram is the end result, but I'm not sure on a few things:

Should there be an empty gap between the supporting 2x10 joists and the outer joists? Meaning, the support around the 4x4 pole is what is needed?

 

Yes, now you are getting the idea of what i was suggesting... but in your picture in post #9, I'd put the 4x4 right next to the outside rim joist, shimming it plumb as needed. You could add a shim block to the side labeled inner frame joist, if you wanted or you could put the nuts on that side, and put your wrench in that void while you tighten the bolt on the outer rim joist.

You would bolt through the post and the two parts that you have labeled 2x10 with two 1/2" bolts after you plumb the post. You would also bolt through the rim joist and post with at least 1 bolt, if not 2 bolts

 

Perfect, that explains things well now. Just to confirm, do you think lug screws would be enough from the 2x10 into the 4x4 pole, or should I use bolts? I was going to use bolts from the rim joist into the 4x4 but wasn't sure if the lug screws would be good enough from the 2x10's.

Thanks again, I really appreciate you spending the time to help.

 

1/2" bolts with washers on each side. Get a 12" long 1/2" drill bit to put in your 1/2" electric drill. Brace the posts so they are plumb and just put a few screws in to hold things together temporarily before you drill your bolt holes clear through.

 

Perfect, thanks!

I noticed you mentioned the following above: "If you center it on a plank, you have to cut a perfect 3 1/2 x 3 1/2 hole in a plank and slip it down over the top of each post, which is NOT a good plan."

I'm not following what you mean by "you have to cut a perfect 3 1/2 x 3 1/2 hold in a plank and slip it down over the top of each post". Do you mind explaining a little more about what is happening here? Sorry again for all these questions.

 

space your posts out so that you notch two deck planks around each post. Parts of the notch will be on two different planks.

 

That makes sense. Okay, reviewing all your comments, do you recommend I install in this order: first, tack all posts to the inside rim joist . then for each post, plumb to get it level and then install the perpendicular joists on each side of the 4x4. Confirm level and them install 2 bolts through the perpendicular joists and 4x4. Last, install 2 bolts through rim joist and 4x4.

does this sound correct?

 

Yes, it's about right. But as you are plumbing g the posts, you will want to take notice of any gaps between the post and the rim. Because if there is a gap, when you put the bolt in, it's going to suck the post one way or the other. So if you see a gap at the rim joist, you need to shim the post using some tapered cedar (or pine) shims.

Installing the 2x10 pieces of blocking is best done first. Because as long as you haven't screwed the blocking in for good yet (just friction fit them, or maybe put 1 screw in each piece to prevent it from falling out) you will be able to plumb that post pretty well on all sides, clamp it... then drill it, bolt it, check it, adjust it and once it's perfect, THEN fasten those pieces of blocking in for keeps.

Then shim the rim as needed and bolt it last, like you said.

They make an inexpensive plastic level just for posts that you might like. It has a bubble on 2 sides so you can look at them both at the same time without moving the level from one side to another. But you will get a more accurate reading with a longer level, like a 72" or 78" level.

Something else you could do as you plumb your posts is fasten one post on each end, then tie a string (chalk line or masons line) around those 2 posts. This would give you a way to check that the 2 middle posts (all 4 really) will be exactly aligned with one another.

And remember like I said earlier, that as you tighten the bolts down, you might be squeezing the post one way or another, and shifting it out of plumb. If that happens, loosen the bolt, give the post a shove in the opposite direction and drop a little more shim in as needed, so that when you tighten it up it will stay plumb.

 

Man, thanks so much XSleeper, I appreciate your help and patience. I'm going to start this project this weekend and will keep you posted.

Have a nice weekend!