How to replace rusting post stirrups?

[Greenforestfair]

We recently bought a new home which has quite a lot to do on it.  We need to replace stirrups on our verandah and are unsure of how to go about that since they appear to have been concreted into the slab? 

We'd like to buy new stirrups of the same type that are currently on the posts and swap them like for like, then perhaps put a decorative post base on each post. Any advice for how we can do that? 

Someone suggested we buy new tall stirrups and cut off the bottom part of the posts but the posts don't look rotted or anything. They were saying they wouldn't be able to use the same bolt holes in the post but I wondered if we couldn't fill the original holes, if necessary.

But what to do about the stirrups being concreted in, if they are? I watched some youtubes but they all had the stirrups in concrete that was separate to the main slab.  😊

[EricL]

Hello @Greenforestfair 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your post stirrups.

A fair bit of exploration will be necessary in regards to the replacement of your post stirrups. It appears that the stirrups are concreted in as there is no evidence of bolt fixings on its footing. It might be necessary to grind away the footing in order to remove it. The builder will then need to determine if a standard Pryda 65x90mm M10 Full Stirrup Post Anchor will work as a replacement.

The existing holes in the post may or may not work with the new post stirrup and will need to be addressed. A taller stirrup might need to be used, and the post trimmed a bit. Support will need to be put in temporarily as the post stirrup is removed and the area will temporarily be fenced off to prevent anyone from walking around the construction area. 

This is a very involved project and will require the services of a builder. I don't recommend doing this as a D.I.Y. project. 

Let me call on our experienced members @Nailbag, @Dave-1 and @AlanM52 for their recommendations.

If you have any other questions we can help with, please let us know.

Eric

[Nailbag]

Hi @Greenforestfair 

The there are no visible signs in the photos, these post stirrups are bolted to the concrete slab not actually in the concrete. Its possible the have been secured with countersunk heads and then coated over with whatever that is over the concrete itself. This stirrup Pryda 65x90mm M10 Full Stirrup Post Anchor that @EricL is the correct replacement.

I can't tell by the photos, but why do you think they need replacing as it's highly unusual they have aged before the bottom of the posts on an older home? Can you see holes forming in the round upright section? If not and your concerned about their condition on the coating, I would use a flap wheel on an angle grinder and wire brush wheel fitted to a drill to remove the coating of each stirrup and check the true condition. If it's just surface rust then continue with the wire brush and then respray them with a rust-inhibiting spray paint.  Bunnings have quite a range to choose from.

If you need to remove them, then using reciprocating saw with a metal blade or hacksaw the bottom of the round post at the base. Then remove the posts screws. You may then need to use a metal grinding disc on the bottom plate fastening heads to cut them off to remove the plate itself. The replacement stirrups would then be fastened into the concrete by simply position the holes in opposing corners to the originals.

Nailbag

[Dave-1]

Good Morning @Greenforestfair 

From the photos you have shown those stirrups do not look rusted? They may be corroded or ?? a little. I would get a brush wheel attachment for your drill as @Nailbag has mentioned and remove the topmost gunk to see what the true state is. 

To replace like for like I would try removing one of the stirrup bolts into the concrete, it may come out but a fair chance it will be locked in place. Even if you remove the stirrup you still should not drill holes so close to the existing holes (as new diagonally oppisite holes) I would suggest to look at larger bottom plates to give a wider spacing to the base for bolts to be put in.

If you can show us some of the posts that have stirrups that are enbedded into the concrete we may be able to come up with some ideas, fist step tho is to remove the top part of teh coating of teh stirrup as they look like they are galvinised and really shouldnt be rusting.

Dave

[MitchellMc]

I’d tend to agree that what you’re seeing on the surface of the mounting plate still looks like it can be treated rather than replaced @Greenforestfair. As long as the rust is only surface level and hasn’t eaten deeply into the metal or weakened the structure, you should be able to restore it. Give the area a good clean using a wire brush or flap disc to remove loose rust and any coating buildup, then apply a rust converter to stop further corrosion. Once that’s dry, repaint the stirrups with a rust-inhibiting metal primer and topcoat to protect them from moisture. This should greatly extend their lifespan without the need for full replacement.

Please let me know if you have any questions.

Mitchell

[Noyade]

Just another set of eyes on the subject.

To me - it just looks like when they painted the concrete they also painted the base of the stirrup.

I'm all for the the advice offered by the learned gentlemen above.

"Someone suggested we buy new tall stirrups and cut off the bottom part of the posts"

I cannot understand why they would suggest that @Greenforestfair? - a longer stirrup is a backward step in my opinion and I see no rot on the wood.

Can you scrape away some of the paint from the base and get back to us?

Cheers.

[AlanM52]

Hi @Greenforestfair,

I am also thinking they don't need to be replaced and it's just surface rust with maybe a some pitting.

Just follow the good advice provided by @MitchellMc and the others and you should be good to move onto the next project.

Cheers

[Greenforestfair]

Thank you Eric.

[Greenforestfair]

Thanks Nailbag.  The prepurchase building report told us that the stirrups need to be replaced, but I can see your point and if we don't have to do that I'll be very happy. 

[Greenforestfair]

Thanks Dave.  The prepurchase building report told us that the stirrups need to be replaced, but I can see your point and if we don't have to do that I'll be very happy.