50's semi poulton le fylde. roof structure?

[yintan]

Go up in the loft & you've got these great big beams sprouting up at a jaunty angle from the centre of the floor, to the middle of the roof, halfway between base and apex

there are 3, something like 6 inch by 3 inch. they all start on top of the house's central wall, and then each one rises at 45 degrees to the centre of each facet of the roof pitch, one per side.

each one appears to support the middle of the really big fat main horizontal roof timber which circumnavigates the roof halfway up.

I could do a nice loft conversion if these great big monstrosities weren't in the way.

Wouldn't dare touch them though in case they are needed to keep the roof up lol.

Question is, were timbers like these a temporary measure when the house was first constructed, just to support the main horizontal timber halfway up, upon which the vertical, thinner, rafters (which carry the felt) rest & are there some settings where they could be removed without detriment?

Or are they likely to be a definite structural neccessity?

 

[joinerjohn]

Structural necessity I'm afraid. . The big fat timbers that circumnavigates your roof are called purlins , the timbers that support these are props. They transfer the roof load safely down to the internal supporting wall and then to the ground. A good architect , in conjunction with a structural engineer would be able to draw up plans whereby you could do a loft conversion though.

 

[RonnyRaygun]

They sound to me like purlin props, and if so are definitely structural.

Have you got any piccies?

You can still do a loft conversion. Removing the props and adding extra support wouldn't be that big a job in the scheme of things...

 

[yintan]

Big thanks guys. Just googled 'purlin props' and yep the pics that come up reflect what I've got.

There's no gable end as such on the house, all the sides of the roof are slanted and the brickwork just forms a square box as it were.

What sort of thing would a structural engineer do to get round it?

 

[RonnyRaygun]

What sort of thing would a structural engineer do to get round it?

Depends on what you are planning to do. If you don't alter the roof structure then it might be a case of adding some steel beams directly under the existing purlins, then building up studwork to give support to the purlins. The beams could also support the new floor joists, which will be needed as the floor will also require strengthening.

If you want to add dormers it becomes more complicated and new steelwork might be required in the roof also.