Repairing purlin

[ajmoore1]

Hi,

I have just bought a house and the previous owner has made some stairs to get into the loft. This has been done without building regs and wouldn't comply. I am not intending using the loft and will remove the stairs and reinstate the ceiling. The only issue is he has cut a section of the 9x2 purlin out as it would have restricted head room on his stairs. The section he has cut out is in the middle and about 5ft. Where it is cut out he has braced it vertically with a bit of 4x2 on to the ceiling joist which are only 4x2 so not sufficient.

My issue is how do I repair this?

I am thinking to cut the purlins at 45degree (scarf joint) and put a piece of 9x2 in and bolt some steel plates across the joints.

Does this sound ok.

Thanks

 

[HERTS P&D]

What did your survey say about it?

Andy

 

[ajmoore1]

Didn't get a survey, property was bought at auction.

 

[freddiemercurystwin]

photo?

 

[maltaron]

If you feel competent you could use a double tenon scarfed joint. Fig 216 here http://www.basiccarpentrytechniques.com/Woodwork Joints/Woodwork Joints 7.html. If not happy to do that there are several simpler alternatives on the same site.

 

[Blagard]

I am thinking to cut the purlins at 45degree (scarf joint) and put a piece of 9x2 in and bolt some steel plates across the joints.

Whist a photo would be really helpful, why try to "insert" a section in line with the purlin. You could probably use a section that well overlaps the existing like a metre each side and bolt together. Use dogtooth washers in between the sections. Some temporary propping might be worthwhile to get the line of the purlins back if sag has occurred, but be careful.

Edit:
The overlap to existing needs careful consideration whether you use plates or an overlapping section of purlin. On second thoughts have a word with a structural engineer for advice. Condition of the remaining purlin could also have some impact on the solution.