Partial attic conversion

Lord Nikon

Basically, I have a truss roof, and need to convert it partially to have space. I would only need room for a computer desk, as I have no room in the rest of the house. The desk it pretty big, and it already in one of the rooms.

Can I remove some of the trusses without fear of the roof landing on my head? If I do remove the trusses, what can I replace them with?

Metric Tensor

No you can't! The trusses are designed as a complete unit including bottom chords, top chords and diagonal bracing so if you start cutting bits out of them you make them useless and then if you plonk a big whopper of a desk on them your desk will rapidly end up sitting in the bed with your missus in the room below.

Even fully intact your attic trusses are probably not designed to be loaded with weight like this on the bottom chord - usually* they are designed to hold slates/tiles on the top chords and ceiling boards etc. on the bottom - all fairly lightweight stuff compared to desks, office furniture etc.

That doesn't mean that you can't convert the attic. It just means you need to hire an engineer to tell you where you need to strengthen in order to reduce timber elsewhere. It will be expensive and messy though! You'll probably need to get structural steel up there somehow.

*specialist ones are sometimes designed to support attic water tanks - but this is of no use to you so no need to worry about it!

Lord Nikon

The desk is light, just big. The weight of a bag of cement.

Gumbo

Lord Nikon wrote: »

The desk is light, just big. The weight of a bag of cement.

Makes no difference. Engineer required and detailed plan to support the roof of you plan on cutting into the truss.

Can be done as a timber exercise using specific bolts, nails and glue in the right place.

BryanF

Please read the forum charter http://www.boards.ie/vbulletin/showthread.php?t=2055036302

Please appreciate section 1.5 is there to protect you.

Calahonda52

Lord Nikon wrote: »

The desk is light, just big. The weight of a bag of cement.

As others have said re the construct: the desk is 1 bag of cement, plus you at how many?:D

Plus the issues with access.

Go back to what we call zero based budgeting and start with looking at alternatives within existing: for the spend you would buy a nice laptop, Xbox, Playstation c/w Virtual Reality kit, and maybe a 4k TV for the footie.

Penn

Lord Nikon wrote: »

The desk is light, just big. The weight of a bag of cement.

The reason the timbers that make up trusses are lighter than a normal cut roof is because the truss is specially designed and engineered. Every part of it is important. Once you start cutting out any parts of them, the way the loading is transferred through the truss changes dramatically.

When you say "remove some of the trusses", I'm guessing you mean the timbers between the rafter and the joists. But the rafter and joist are part of the truss too, not just the middle bit. They're all part of the one piece and you can't remove part of that piece without seriously compromising the other parts.

If you're cutting out any of the timbers, regardless of whether it's a desk or a bag of cement or even if you're just cutting it out to make a bit more room, the actions of the timber you're cutting out have to be replaced, and the only way you're going to be able to do that is to get it properly assessed and designed by a competent professional.