anchoring railing posts to rubber roof

[homi_]

I'm laying a trex deck on a rubber roof with 2x4 sleepers. what's the best way to anchor the railing posts? the railing posts will be sleeves over PT 4x4

the best idea I've come up with so far is pouring concrete into a form that makes a 4x4 concrete column with a base that extends ~8 in each direction under the trex planks.

also made a base out of 2x4s attached perpendicularly at the base of the 4x4, but these tear through bottom of the 4x4 when loaded

any other ideas?

thanks homi [e-mail]

[DiezMon]

You could just lag-bolt the 4x4 to the 2x4s. You could then add more support around the post by running two 2x4s' on either side of it between your sleepers. Then you'd have three 2x4's around the post at it's base.. know what I mean? Don't forget to cut a small arch out of the perp boards, for drainage.

I wouldn't mess with pouring concrete.

Tim

[tom]

h wrote: I'm laying a trex deck on a rubber roof with 2x4 sleepers. what's the best way to anchor the railing posts? the railing posts will be sleeves over PT 4x4

Sleeves? Made of what material?

the best idea I've come up with so far is pouring concrete into a form that makes a 4x4 concrete column with a base that extends ~8 in each direction under the trex planks.

also made a base out of 2x4s attached perpendicularly at the base of the 4x4, but these tear through bottom of the 4x4 when loaded

any other ideas?

Well, I hope you own the roof! But seriously, Trex needs to be supported every 12 inches, so your 16 inch concrete base idea would allow the decking to sag in those areas. And they should be able to stand up to a drunken stumble. Best way is through the roof, bolted to the rafters, then repair the roof around each protrusion with cant strips and a good flashing job. Can you lag your posts through the fascia into the rafters? And, I'd run my sleepers parallel to the direction of water run-off. Gluck. Tom

[homi_]

I was thinking the same thing I tried this using the 2x4 sleepers around the 4x4, but the bolts shear out of the end of the 4x4. (the sleepers are lying flat on the roof, so the bolts end up being only ~3/4 inch from the end of the 4x4, with the grain, etc...)

Another idea I was thinking of was to cut 4' plank of 2x12 into a large inverted T shape. The base being the 12" dimension and cutting the shaft of the T to 4" width. I'd bolt 2 together and then essentially have an integrated 4x4 with 12" base that could sturdily attach to the sleepers. I'll try it tomorrow and let you know

thanks for the help homi

[homi_]

the composite rail posts slide over 4x4

the sleepers are 12"oc and I'd run the sleepers right up to the comcrete base (so sleepers every 12" next to a solid 16" concrete base) and then fasten the trex right into the concrete base.

I agree rail posts mated to rafters would be optimal, but I'd prefer to avoid tearing up the roof if possible.

thanks for the help homi

[homi_]

I was thinking the same thing I tried this using the 2x4 sleepers around the 4x4, but the bolts shear

out of the end of the 4x4. (the sleepers are lying flat on the roof, so the bolts end up being only ~3/4 inch from the end of the 4x4, with the grain, etc...)

Another idea I was thinking of was to cut 4' plank of 2x12 into a large

inverted T shape. The base being the 12" dimension and cutting the shaft of the T to 4" width. I'd bolt 2 together and then essentially have an integrated 4x4 with 12" base that could sturdily attach to the sleepers. I'll try it tomorrow and let you know

thanks for the help homi

[DiezMon]

that little 4" Tee coming off of a 2x12 isn't going to be very strong. With the way the grain runs, you could probably break one of those off with your hand.

You may want to think about bringing your posts in an inch or two, so you're not so close to the end of the sleepers... Or, find some appropriate angle iron that will help you out.

Is it too late to switch to 2x6 instead of 2x4?

Tim