How to join a pre-existing wooden beam?

[vanda99]

I have to remove and move a car port post but the beam it supports has a join exactly on top of the post above it. (I doubt there is a through bolt joining the 2 parts of the beam but I suppose having the join on top of the post was a reasonable method when it was first built). Its a 48 x 200 mm beam 

Can anyone recommend a suitable way of joining the 2 parts of the the beam, like some sort of bracket or length of steel with bolt holes that could bolt across the join. The various sorts of brackets i have seen at Bunnings, in the section with rafter hangers and the like seem too light - there are some lengths of solid hot dipped steel but they are less than 300 mm long with only 3 bolt holes with one uselessly in the middle.
Oh similarly there is a rotten section i would like to splint with something suitable

Any thoughts gratefully received 

[EricL]

Hello @vanda99 

Thank you for sharing your question about your wooden beam in your carport. 

In order to give our members a better idea of what you are working on, would it be possible for you to post a photo of the post and beam in the carport? Once they see the beam, they'll be able to provide you with recommendations on how to move forward. We would also like to request for a photo of the rotted section so that we can assess its condition as well. 

Another possible option for you to join the two beams above is to use structural timber as well, this is on the condition that there is space available. But this type of repair will require the services of a structural engineer as they will need to assess the current load condition of the beams. The structural engineer will also be able to tell you if moving the post is a viable option or it will need to go back to its original spot. 

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

Eric

[vanda99]

Ok thanks. Images attached. I wont be hiring a structural engineer for this little job (if I could get one). If i could afford that i would get someone to do the job too. But i hoped this group would on the basis of previous experience be able to provide some ideas on how to improve on the original work. My new post will help but at worst i will just replace the original post and let the base of the post rot again. 
Cheerd

 

  

[Noyade]

I'm sorry @vanda99 I'm usually rather slow with understanding the problem at times on this site.

Is it the three-way connection at top?

"bracket or length of steel with bolt holes"

My thought is 100mm X 5 mm steel plate, welded and pre-drilled to form a large 'T' bracket.

Is that what you're after?

Cheers.

[MitchellMc · Accepted solution]

Hi @vanda99, 

Unfortunately, it simply cannot work the way you are hoping. You cannot take two beams that were never structurally joined, remove the post they were both relying on, shift that post elsewhere, then bolt the beam ends together and have that act as a structural support. Any bracket you add in that location is not a substitute for a supporting post. It will not carry roof loads the way the original post did.

In standard construction, we do not join beams end-to-end like that for exactly this reason. There is no structural bearing surface and no accepted fixing method that would make the connection safe under load. Although you do not want to involve a structural engineer, one really is required to assess this properly because the request itself is asking for something that is outside normal building practice.

Is there a particular reason you cannot simply remove the old post and install the new post in the same position? That is the correct method. You prop the beams on either side, remove the degraded post, and install a new one exactly where the old one was. The beams then sit on a proper bearing point and the problem disappears.

I cannot recommend any end-to-end connector or bracket for this situation because it would leave the beams unsupported and relying solely on a mechanical fixing, which is unsafe when roof loads are involved.

Please let me know if you have any questions.

Mitchell

[Noyade]

Sorry. Yes - I did misunderstand the problem - again. I thought the second photo down was the issue. I didn't even notice the newly installed post.

😕

[vanda99]

Thanks Mitchell. I am tending to agree with you - it was originally a pretty sloppy way of doing it - but i am trying to exhaust all possibilities. Years ago i myself joined beams but constructed a wooden joint, even if a simple one midway between posts, so i know how it should have been done. 
The reason i couldnt simply replace the post is because the original thing i was doing was replacing the post because it was 8 cm below ground level (ie 8 cm below adjacent carport slab) and therefore rotten. - so its not really doing what it should be doing. ( and i didnt even notice or think about a beam join problem as from the inside of the car port the join was covered by the post joint!! ) 

Some options - 

(1) replace it with a steel post in the existing stirrup and concrete around it up to ground level

(2) cut the old stirrup off. Drill holes into the old concrete to take thread to accimodate a new bolt on stirrup (making say a 300x300mm  concrete pad over the top of it but with the thread still proud 10 or so cm)

(3) put in a second post 15cm to the left of where the original post was to match the post i already have put in 15 cm to the right of where the original post is. There will then be a post virtually at the end of each beam so should be ok especially if I tie them together.

Not familiar with (1) though i do seem to see the results in shopping centre verandahs and the like. 

(2) is probably THE standard correct way - no questions asked- but since i already have a new post to the right of the offending original post it would be quite straightforward to just add a post to the left. Both beam ends would then be essentially supported but i think i would still need to gang nail something across the join. 
Any more thoughts very welcome 

[Noyade]

"8 cm below ground level (ie 8 cm below adjacent carport slab)"

At the risk of embarrassing myself yet again @vanda99 , which I'm happy to do.

My impression is you're OK for a steel or wood post to be positioned to support the 'joined' beam, in the original location - but the stirrup is too low?

Assuming yet again - you're going to continue concreting, extending the level/width of the carport?

Is it possible for you to extend the height by welding two plates with pre-drilled holes. Insert the new post - which supports the joined beams and then you're free to concrete around it and onward you go.

Distance 'A' now brings you above the carport level.

Something like this...

If I'm still wrong - let me know.

I have lots of ideas. 😉

[vanda99]

Hi Noyade

Thanks for continuing to think it through and the great diagram. You are spot on and its probably what i should have been doing with this post and the other 5, but i am not a welder so i have been trying to work around other options

Also considered bolting on some steel plate but not sure bolting is ok. 

cheers