Garage roof

[Ab12]

Just finished the single skin blockwork for my double garage and moving onto the roof next

The double door opening has a steel in position, the top of which finishes at the same level as the rest of the walls (side and back)

I now need to move onto building the flat roof structure and am trying to figure out the most appropriate way to do this.

The roof is going from back wall to front (steel end).

What are the options here for fixing.

1. Wall plate fixed to back wall with mortar and strapped, and bolted to steel at front, rafters across from front to back fixed with nails, twist straps used to fix every other rafter to the walls.

2. Rafters straight on top of steel and ontop of walls

Q. Here, how are the rafters fixed down to the blockwork wall and the steel itself?

Q. Either way, when I get to the side walls do I fix a rafter to each side wall? If so, how as these side walls will not have a wall plate?

Thanks

 

[noseall]

Just finished the single skin blockwork for my double garage and moving onto the roof next

The double door opening has a steel in position, the top of which finishes at the same level as the rest of the walls (side and back)

I now need to move onto building the flat roof structure and am trying to figure out the most appropriate way to do this.

The roof is going from back wall to front (steel end).

What are the options here for fixing.

1. Wall plate fixed to back wall with mortar and strapped, and bolted to steel at front, rafters across from front to back fixed with nails, twist straps used to fix every other rafter to the walls.

2. Rafters straight on top of steel and ontop of walls

Q. Here, how are the rafters fixed down to the blockwork wall and the steel itself?

Q. Either way, when I get to the side walls do I fix a rafter to each side wall? If so, how as these side walls will not have a wall plate?

Thanks

Or just stick a wall plate on top of the wall, fix the joists to the plate and strap the plate down. Or you could just lay the joists directly to the top of the wall and build them in and use a twisted strap on every third joist, along with a series of binding noggings along the ends of the joists.

 

[Ab12]

Or just stick a wall plate on top of the wall, fix the joists to the plate and strap the plate down. Or you could just lay the joists directly to the top of the wall and build them in and use a twisted strap on every third joist, along with a series of binding noggings along the ends of the joists.

If directly to top of wall I get I can use the twist straps, but if directly ontop of steel, how are these secured?

Thanks

 

[noseall]

If directly to top of wall I get I can use the twist straps, but if directly ontop of steel, how are these secured?

They aren't secured to the steel, rather they are secured to neighbouring roof elements.

 

[noseall]

If directly to top of wall I get I can use the twist straps, but if directly ontop of steel, how are these secured?

Did you have the steel drilled?
If we are anticipating fixing to either the web or the flange, we have the suppliers fabbys drill them for us.

 

[Ab12]

Did you have the steel drilled?
If we are anticipating fixing to either the web or the flange, we have the suppliers fabbys drill them for us.

They are not, but out of interest when drilled are you just sitting the rafter on top of steel and then fixing through steel into wood with screws?

 

[noseall]

They are not, but out of interest when drilled are you just sitting the rafter on top of steel and then fixing through steel into wood with screws?

No.
If we are fitting on top of the steel, we would bolt a plate to the top of the flange, and then fix the joists to the plate.
Or if we were fitting AT steel height (rather than on) - either slot into the web or fill out the web with timber bolted to the web and connect with joist hangers etc.

You can even fix the joists inbetween the two scenarios, as long as you fit out the steel correctly, with bolted timbers.

 

[Diver Fred]

Which way is the roof 'Fall' (the slope)? which way is the longer run?

 

[Ab12]

It's 6m wide 5.1m deep. So the fall will be across the 5.1m back to front (into gutter above double garage door and then into drainage leading to soakaway)

I think I'll go with the wall plate option, with the wall plate tied down and some twist ties for good measure, and then bolted into the steel.

What is the best course of action for the side fascias? The last rafter, I assume will end just inside the end (each side) of the building, but then in order to attach side fascias I need some wood hanging on the side there/flush with side of building? So here what is the course of action?

Thanks

 

[Ab12]

No.
If we are fitting on top of the steel, we would bolt a plate to the top of the flange, and then fix the joists to the plate.
Or if we were fitting AT steel height (rather than on) - either slot into the web or fill out the web with timber bolted to the web and connect with joist hangers etc.

You can even fix the joists inbetween the two scenarios, as long as you fit out the steel correctly, with bolted timbers.

Out of interest, when you fit at steel height and the steel is the finished front of your building, how do you then fit fascias to this steel at the front and finish the front?

 

[noseall]

Out of interest, when you fit at steel height and the steel is the finished front of your building, how do you then fit fascias to this steel at the front and finish the front?

You have the steel fabricated it so that it accepts whatever has been detailed there by the designer. I wouldn't for example just plonk a lump of steel on the front of an extension, without understanding what happens next.

I have the steel drilled ready to except timber and cladding where necessary..

Crank1

• noseall
• 3 Dec 2021

Crank5

• noseall
• 3 Dec 2021

Key

• noseall
• 12 Feb 2022