Sinking Conservatory Roof

[DavidJW]

I moved in last April and now the roof of my lean-to conservatory is starting to sink in the middle. I think it must be due to the recent high winds as the conservatory is facing south and we have had a nearby fence down. I don't know what make the conservatory is and have a feeling that it was a DIY job as the previous owner was a "builder/roofer".

I have posted a series of photos at
http://uk.pg.photos.yahoo.com/ph/dj...done=http://uk.photos.yahoo.com/ph//my_photos

They show two wooden beams supporting the upvc roof. (And a prop to stop it collapsing further!) The beam between the house wall and the conservatory doors seems to have broken.

I have now received two conflicting solutions. The first person said that the broken beam was doing nothing and that the answer is to remove both beams and replace the "purlin" one with a steel beam under tension between the two side walls. The glazing bars would rest on adjustable upside down feet along the length of the beam. Cost £1900.

The second person said that this was unnecessary as the real problem lay with the strength of the beam from wall to door. He suggested replacing the wooden beam with a steel Universal Beam. The problem here is that the architrave above the french doors may not be strong enough to support the extra weight and would need strengthening. I have no idea how much this will cost though the U-beam will cost about £200.

I have insurance but the person suggesting the first solution doubted if they would pay for the repair as, in his opinion, the roof had not been properly constructed in the first place.

I have found it virtually impossible to find local firms who will repair conservatory roofs - replace, no problem. One repairer was not interested when I said it was a possible insurance job.

I am now in a dilemma as to what to do next and would appreciate some help.

 

[^woody^]

Your insurance should cover it.

There are other options better than a steel beam.

You could fit an 8mm steel angle section (50w x 100d) bolted to the side/bottom of the main timber.

The problem is, if the main timber is the one running from the house to the conservatory door, then how will an angle peice be supported above the door? And will any extra weight bow the door frame?

If the main timber runs from the sides of the conservatory, then it seems a bit of a long span, so the angle steel may need calculating

Alternatively fix two 5mm plates (by 2m long) either side of the bowing timber in the centre of the span. Jack the timber up so it is level, fixed the plates, and so when the support is released, the plates keep the timber from bowing

I would go with the second option.

 

[DavidJW]

Alternatively fix two 5mm plates (by 2m long) either side of the bowing timber in the centre of the span. Jack the timber up so it is level, fixed the plates, and so when the support is released, the plates keep the timber from bowing.

Could you explain this a bit more - I am confused

Do you mean: put a 2m long plate on each side of the beam from house to window? I think the purlin is in two pieces - you can see steel straps in the photo connecting them to the mainbeam - so it should be possible to remove them while the metal plates are fixed.

The thickness of the plate is 5mm - yes? How wide would it need to be?

Can you suggest a better way of fixing the purlins to the main beam?

 

[^woody^]

By main beam I mean the one which is supporting all the others. I presume this has defelected due to the load.

The idea is to get the beam straight, and then fix two plates to keep it straight. The 2m length is arbitary, I have assumed that this is the major part of the centre deflection, so should be enough, but it may need 2.5 or 3m.

I would use 75mm or 100 wide steel, and a 8mm bolt every 400mm staggered ie like this . ' . ' . ' . and say 25mm in from the edges. Thinking about it 3mm steel plate should be OK

You could reattach the other timbers by screwing a speedy joist hanger to the main beam.

Now, this is just a concept to get you thinking. I can't be certain of the exact sizes without seeing the roof. But we have successfully done something similar.