strengthing a purlin

[gastight]

I've removed a chimney, which sits 3/4 of the way from the gable on my wing building, down to the roof level. I am going to a re-roof.
I've two sections of purlin. One sits from the gable end to chminey and the other is from chimney to main buidling of the house.

I've like to remove the chinmey all the way down. which means putting one new rafter in. What is the best of stengthing purlin ?

1. Put a brand purlin from the gable to main building
OR

2. bolt a section to the two purlins. Will this provide enough strength

 

[masona]

2. bolt a section to the two purlins. Will this provide enough strength

This would be the easiest way to go, use coach bolts, square washer and timber connector, make sure the new purlin have plenty overlap as much as possible and also stagger the bolt holes every other one.

 

[chappers]

tat would work but do bear in mind that say if one of the purlins is 5 m and the other is say 6m then you will in effect be creating an un supported purlin of over 11m which is realy a bit long.

 

[gastight]

chappers

The purlin is in the loft. The overall length is approx 8.5m;
1 section is 2m an the other section is about 6.5m. The joists on are only 3 x 2. I may put a vertical support half down the purlin resting on the 3 x 2 joist. OR should I put 8 x2 joist under the veritcal support

 

[masona]

What is the ex-chimney width?

Are you saying you have 2m purlin to the chimney then the other side is 6.5m which shouldn't give you 8.5m overall?


The purlin is in the loft. The overall length is approx 8.5m;
1 section is 2m an the other section is about 6.5m.

 

[gastight]

Sorry Masona. I should have been more clearer

Overall length is 8.5m

1 section is approx 2m

chminey is approx 0.5m ( may be a touch more)

2nd sections is approx 6m


I'll measure up accurately tonight

 

[masona]

The way I would do it, is to take out the 2m purlin and renew 2.5m to meet up the 6m purlin and put timber the same size as the purlin on both side starting at the 2.5m flushed by the end wall say approximately 5m/6m length with nut, coachbolt, square washer & timber connector. You may need to do a temporary support on the rafters where the missing purlin is while you're doing this.

Will also need some big G-cramp to do this.