Joist hanger question

[amsie]

Hi all,

Can you use joist hangers on this breeze block wall with wall plate on top as shown in the photo and what joist hangers shuld I use?

Untitled

• amsie
• 28 Mar 2013
• 1

The 6x2 joists will be to support a ceiling.

The wall plate will also have rafters sitting on it.

Thanks in advance

Paul[/img]

 

[^woody^]

Not in your case, as the joists act as ties to the rafters and so should be fixed to them

 

[amsie]

Woody,

In this case the original plan was to have an open vaulted ceiling with velux's, without a ceiling tie, which the Architect has done the calcs for and has been approved. However, we can't get a 15degree angle on the roof without building round the windows. Why the Architect didnt pick this up don't ask.

So without the velux's we've decided to go for a flat ceiling instead. If we put in 6x2 joists, we can get the new ceiling to match the existing height, otherwise, the blockwork on the extension would have to be lowered 150mm.

So in this case can we drop in 6x2 joists using hangers?

 

[^woody^]

If the roof is otherwise restrained as per the original plan, then yes you can drop joists onto hangers

The hangers should ideally be the type that wrap over the plate and drop down the back - these may be speedy hangers or the better quality masonry ones

 

[amsie]

Thanks Woody much appreciated.

 

[tony1851]

Woody,

Why the Architect didnt pick this up don't ask.

And how much did he/she charge you for the defective plans?

 

[RonnyRaygun]

otherwise, the blockwork on the extension would have to be lowered 150mm.

Out of interest, why not drop the blockwork 150mm? Doesn't seem like a lot of work to get the vaulted roof that you want.

Not in your case, as the joists act as ties to the rafters and so should be fixed to them

I keep saying it...rafters on a lean to roof never require ties...

 

[^woody^]

I would do this

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• ^woody^
• 20 Jan 2012
• 5

Or change the tiles and roof lights

 

[tony1851]

Or change the tiles and roof lights

Is there a rooflight which works below 15 deg.?

 

[^woody^]

A flat roof light, or a specialist made one will do.

But I wonder what the tolerance is from the stated 15° pitch for typical rooflights? May be as low as 12°

 

[tony1851]

But I wonder what the tolerance is from the stated 15° pitch for typical rooflights? May be as low as 12°

You may well be right in practice, but I've known some inspectors refuse to pass a job if the roof wasn't to the minimum pitch specified by Velux.

 

[pinenot]

From the Velux online site -

Q. "Is installation of VELUX roof windows possible at any roof pitch?
A. Yes. Centre-Pivot Roof Windows are designed to be installed on a roof pitch from 15°-90°, depending on the roofing material and flashing selected. Top-Hung Roof Windows are designed to be installed on a roof pitch from 15°-75° (55°-75° with the use of special springs), again depending on the roofing material and flashing selected. VELUX also offer a range of flat roof solutions which can be installed on roofs with a pitch from 0°-15°."

 

[limerockconstruction]

otherwise, the blockwork on the extension would have to be lowered 150mm.

Out of interest, why not drop the blockwork 150mm? Doesn't seem like a lot of work to get the vaulted roof that you want.

Not in your case, as the joists act as ties to the rafters and so should be fixed to them

I keep saying it...rafters on a lean to roof never require ties...

I'm with Ronny - pop the wall plate and a course of blocks, run in a course of bricks, should take an hour at most - won't cost you any more than the ceiling detail and it will give you the desired effect.

 

[masona]

Untitled

• amsie
• 28 Mar 2013
• 1

Might be an idea to re-cut the wallplate to the centre of the ladder and put the restraint straps there, might be weakness and awkward for the plasterer

 

[tony1851]

VELUX also offer a range of flat roof solutions which can be installed on roofs with a pitch from 0°-15°."

Yes, they supply those dreadful boxes which look like gun turrets on tanks.