Porch post conundrum

[billconner]

Received porch posts for porch addition. Attached is the installation instructions I downloaded.

How would you attach posts to floor with the aluminum plinths?

FWIW, these match the profile of existing just about exactly. Pleased. The existing posts, there for 30 years and seem fine, are not on plinths, just set and toe nailed into porch floor decking. I have considered that but of course warranty says they have to be on the plinth. Not sure existing are hollow.

 

[BillK]

Do they really need to be attached to the floor ?? The overhang over my front walkway has 4x4 posts sitting on aluminum stands and they are not attached to the concrete walk in any way. I guess the weight of the roof has kept them in place since 1978

 

[cgrutt]

I might throw a bit of construction adhesive under the bases but weight should keep it in place. If you're concerned about it moving could you put some trim around the base and fasten that to floor?

 

[Uncle murph]

Received porch posts for porch addition. Attached is the installation instructions I downloaded.

How would you attach posts to floor with the aluminum plinths?

FWIW, these match the profile of existing just about exactly. Pleased. The existing posts, there for 30 years and seem fine, are not on plinths, just set and toe nailed into porch floor decking. I have considered that but of course warranty says they have to be on the plinth. Not sure existing are hollow.

You attach the aluminum base to the column,gravity pushes the little tangs in to the deck.I have installed and replaced dozens and dozens of columns and have never seen the bases attached to anything except the columns.

 

[billconner]

Open porch with roof. I was worried about wind and uplift.

I was trying to think of a way to attach a wire rope or chain or all thread "in" the post and a small hole saw in middle of base and anchor it to porch floor framing.

Existing are toe nailed in.

 

[MikeC55]

Yea, uplift is the only thing I can think of that would require attachment to floor. Hurricanes are probably not too common there...

 

[jar944]

My porch posts were only held by gravity both top and bottom.

 

[KenC]

I've had similar situations where uplift is/was a concern. On a wooden deck one can use long screws at an angle, 'toe-screwed'. Use a drill designed for Kreg screws and source a few of the plugs they make for the holes when exposed. If your painting they'll disappear.

 

[PCustoms]

Open porch with roof. I was worried about wind and uplift.

I was trying to think of a way to attach a wire rope or chain or all thread "in" the post and a small hole saw in middle of base and anchor it to porch floor framing.

Existing are toe nailed in.

What does the hollow measure?

You could slip a short post (4x4?) through the plinth and into the column, then screw that to deck.

Is this all just sitting on the decking?

 

[mike93lx]

I have the same on my porch. They used a couple nails to locate them for install, but otherwise nothing for uplift

 

[BillK]

Open porch with roof. I was worried about wind and uplift.

Existing are toe nailed in.

I doubt that toe nailing would really help prevent uplift from the wind. If you are really that concerned about it you could probably drill and countersink a couple of holes in the aluminum bases an put a couple of stainless construction screws in.

 

[PCustoms]

I doubt that toe nailing would really help prevent uplift from the wind. If you are really that concerned about it you could probably drill and countersink a couple of holes in the aluminum bases an put a couple of stainless construction screws in.

How would you attach the aluminum to the deck, and then the aluminum to the post?

 

[mike93lx]

Could drill a pocket hole then screw the post to the deck framing with something like a long truss screw and plug the hole.

 

[coldh2o]

Info provided is lacking details on exact dimensions, location, existing structure, but suggest the following with appropriate site-specific revisions:

Place the base on the deck in the proper location, upside down. Drill small diameter pilot holes through the deck, centred in the four screw holes in the base. place base and post in final location. Screw appropriate length GRK's up through pilot holes from under deck, into the post.

 

[PCustoms]

Info provided is lacking details on exact dimensions, location, existing structure, but suggest the following with appropriate site-specific revisions:

Place the base on the deck in the proper location, upside down. Drill small diameter pilot holes through the deck, centred in the four screw holes in the base. place base and post in final location. Screw appropriate length GRK's up through pilot holes from under deck, into the post.

I'd probably do something like this...

Buy ad reinforcement/blocking to deck, instead of relying on decking.

 

[coldh2o]

I'd probably do something like this...

Buy ad reinforcement/blocking to deck, instead of relying on decking.

For sure. Probably a good idea to add blocking to fill the void in the bottom of the post too.

 

[Hank11]

For sure. Probably a good idea to add blocking to fill the void in the bottom of the post too.

Maybe not close up the hole, but staple some metal screen to keep insects from nesting.

 

[BillK]

How would you attach the aluminum to the deck, and then the aluminum to the post?

I was thinking he could drill a couple of holes in the side of the aluminum in the corners at an angle. It would be ugly but might help a little.

 

[billconner]

I doubt that toe nailing would really help prevent uplift from the wind. If you are really that concerned about it you could probably drill and countersink a couple of holes in the aluminum bases an put a couple of stainless construction screws in.

Makes me smile because I thought same thing but how do you screw plinth to floor and to post?

But glad you posted this. It made me think of using machine screws, get that all drilled, wood screw plinth to post, and then hopefully get machine screws to drop into holes.

Great post!

 

[billconner]

I see others saw this option also. The manufacturer suggests wood screws into end grain, a little questionable.

I think it's intentionaly "hollow" to help it dry, so don't think I should block that in anyway. coldh2o's wood screws from under is interestion but the machine screws appeal, perhaps with a plate. I'm thinking 2 1/4-20s is more than whatever wood screws do into post. And each post "straddles" a 2x6 joist. I planned that after seeing most of existing 10 only sit on 5/4 x 6 decking.

Or I'll skip plinths and do what kenc suggested - screws tied into decking and at least 2 of 4 into joist. Might core through decking so air can circulate but not sure joist will allow that.

 

[CraigStu]

I'd install as they suggest. Then I'd toe-screw. Predrill through the bottom of the posts and through the aluminum and run a pair of something like 1/4" GRK screws down into the deck. Since you might end up w/ a bit of screw head showing, I's then use some 1x6- 1x10s to build a cover around the base. Or how about similar to these?

https://www.amazon.com/ORIGLE-Internal-Powder-Coated-Standard-Handrail/dp/B0F6V2WKNF/?tag=atomicindus08-20

or

https://www.lowes.com/pd/Nuvo-Iron-6-in-x-6-in-Powder-Coated-Black-Aluminum-Deck-post-base-trim/5015997603

Screw these to the deck and to the post.

 

[Fav Onefour]

Main goals with the mounting is to keep the posts in place and prevent rotting. I bet the plinths are mainly designed to help prevent rot issues on concrete.
This is from my front porch circa mid 1980s.

The exterior cladding was cedar. The post inside was untreated 2X wood sitting on an anchored block.

The anchors were mainly there to keep the posts from "kicking out".
I was dealing with concrete base so I went to composite standoff plinths. Simpson has a whole system for that setup and their recommended anchoring is a single rod inside the post base.

There are less rot issues on wood decking but that is still the first place it will happen.

I bet it wouldn't be too hard to make a rod or steel dowel base that fits inside your plinths. That would allow to attach the plinths to your columns and tilt the columns into place.

 

[billconner]

I'd install as they suggest. Then I'd toe-screw. Predrill through the bottom of the posts and through the aluminum and run a pair of something like 1/4" GRK screws down into the deck. Since you might end up w/ a bit of screw head showing, I's then use some 1x6- 1x10s to build a cover around the base. Or how about similar to these?

https://www.amazon.com/ORIGLE-Internal-Powder-Coated-Standard-Handrail/dp/B0F6V2WKNF/?tag=atomicindus08-20

or

https://www.lowes.com/pd/Nuvo-Iron-6-in-x-6-in-Powder-Coated-Black-Aluminum-Deck-post-base-trim/5015997603

Screw these to the deck and to the post.

If all new that might work, but not crazy for the look. Considering I'm adding on with 3 and there are 10existing and fully loaded, not able to put those collars on. But thank you.

 

[billconner]

Main goals with the mounting is to keep the posts in place and prevent rotting. I bet the plinths are mainly designed to help prevent rot issues on concrete.
This is from my front porch circa mid 1980s.

The exterior cladding was cedar. The post inside was untreated 2X wood sitting on an anchored block.

The anchors were mainly there to keep the posts from "kicking out".
I was dealing with concrete base so I went to composite standoff plinths. Simpson has a whole system for that setup and their recommended anchoring is a single rod inside the post base.

There are less rot issues on wood decking but that is still the first place it will happen.

I bet it wouldn't be too hard to make a rod or steel dowel base that fits inside your plinths. That would allow to attach the plinths to your columns and tilt the columns into place.

Indeed the post manufacturer is much more concerned about rot. Reason for plinth and not using it voids warranty. I think machine screws - SS 1/4 20s - will work. I found table in code and will design for 320 pounds of up lift per post. Manufacturer finally got back and said weight of post and roof is all that's needed and they're in southern Alabama. They're much more focused on using plinths, not blocking core, and coating top and bottom with high performance exterior caulk. Great another pair of jeans ruined by caulk.

 

[CoogarXR]

Yeah, my porch post rotted out from sitting right on a concrete slab. I realize your deck isn't concrete, but I'm bored and I wanna share my crapola anyway. I posted about my home-made plinths and what I used the hollow-core of the post for in the "repurposing thread"

The repurposing thread

Way back in the late seventies and early eighties. Looks like I have an extra decade under my belt.

www.garagejournal.com

I did end up screwing my plinth to the slab with tapcons (just on the outer two sides, so you can't see fasteners from the house-side), since sometimes we wrap a dog rope around the post. Last time my sister-in-laws clydesdale-dog pulled the old post right off (since it wasn't connected at the bottom).

 

[Hank11]

If those plinths or post bases were just about an inch bigger on each side, this would be a real simple thing to fix.
Maybe buy different ones?

 

[billconner]

It would change the appearance quite a bit from existing.

I think if doing it over I'd just toe posts to deck plus sealant and core a hole so air can get to center. Part of that is at my age I don't expect to be around here in 10 years, plus existing are fine after 30.

It was not hard to have bolts preset in plinth and predrilled in deck and just set post on marks. Bolts went in easy.

I couldn't get flat head ss longer than 2" so used round head and had to put a divot in post but not hard. All in all, not bad, but wished manufacturer had worked it out.

 

[Hank11]

If you’re putting up all new posts, I don’t think you changed the appearance that much at all and if it did, it’d probably look better.

Classical order - Wikipedia

en.wikipedia.org

 

[billconner]

That's the point - adding 3 keeping 10 as is. Searched a lot to find a close match.

 

[Hank11]

I would replace them all — it’ll look nice and the old ones will probably last a lot longer if they’re held up out of any water.

 

[billconner]

I'm glad you have an extra $4000-5000 to spend, doubling the cost of the project. GJ loves to spend OPM.

 

[mike93lx]

I'm glad you have an extra $4000-5000 to spend, doubling the cost of the project. GJ loves to spend OPM.

It is awfully fun!

 

[Hank11]

I'm glad you have an extra $4000-5000 to spend, doubling the cost of the project. GJ loves to spend OPM.

No! Just replace all the bases. Keep the old posts. It should not be a lot of money. Maybe 2-300 bucks.

 

[billconner]

The existing posts are loaded and in good condition. Why would I mess with them at all? Makes no sense.

 

[billconner]

Just for clarification, new and exist.

 

[PCustoms]

Just for clarification, new and exist.

This clarified nothing!

J/k

 

[billconner]

It won't let me post new. Been trying.

That was weird. Ended up deleting a lot and starting over.

 

[mike93lx]

It won't let me post new. Been trying.

The new post is on the right

 

[PCustoms]

It won't let me post new. Been trying.

Even the forum is preventing you from using new posts...

 

[Hank11]