Shelving spanning a 3m gap

[webbier]

I thought this was the most appropriate place for this question and I know it's not quite woodworking I hope it was close enough that I may get some help.

I want to put shelving above our garage door. The span for the wood would have to be 3m. They won't have super heavy things on just because of the space left available but there will be quite a bit.

According to some span tables, if I'm reading them correctly, I'd be looking at 38 x 170 or 38 x 145 beams. But they seem to be for floors/house building rather than shelving.

So my question are:
Do those beams sizes sound right?

How would you attach them to the wall? A batten or wall hangers?

Is there a way to use smaller beams? E.g. bonding/bolting on an aluminium profile to prevent sagging.

 

[ChaiLatte]

Your post lacks so much information, it is impossible to give useful advice.

Draw a diagram showing the walls and roof of the garage and the proposed shelf.

Span tables are produced for a particular purpose. The 'governing criteria' they use to list any section size is one of deflection (the figure of span/120 comes to mind). This is important if you are walking over a floor. It is less important to a few paint tins and a set of rusty hedge shears.

 

[Setch]

How deep is the shelf going to be?

Will it be attached/supported along the back edge? (If there's a bulletproof lintel this might be tricky)

A relatively shallow shelf, fully supported along the back will need far less meat at the front to do the job. Additionally, a utilitarian garage shelf may tolerate a bit of sag/deflection underload without it being an aesthetic issue, unlike a showpiece bookshelf in the living room.

 

[worn thumbs]

If the OP hasn't used it previously,this might be a good use for the sagulator. The Sagulator – WoodBin

 

[webbier]

The shelf will be about 80cm deep and can be screwed in to a wooden beam that is above the door on one side. So I guess it's just the 'open' side that would be subject to sagging.

So if the shelf is 80cm deep and I use 3 beams and one is screwed to the wood above the garage doors and I put some noggins in it feels like it would be pretty strong but I'm still unsure what size timbers I can 'get away with'.


Regarding the diagram I am not sure what help it would be or even how to draw it. It's just two walls that are 3m apart. Supports going up to the ceiling aren't an option either.

 

[Chrispy]

Three 4" x 2" joists hung on Joist hangers nailed to the walls with a bit of plywood or Chipboard flooring will be OK it will sag a bit but so what.

 

[Lons]

It is likely to sag a bit even under it's own weight, is there an option of a mid point support up over from the shelf front to roof timber's? Could be wood or a builders strap or even other metal if you have any lying around, doesn't need to be heavy guage.

 

[webbier]

No, unfortunately no option to get to the ceiling for support

 

[Sachakins]

You could mount several short twin slot shelving brackets.

This type

 

[Sachakins]

80cm 32" is very deep for a shelf!

 

[webbier]

We don't have any loft storage so our only space for that stuff is to be on this shelf/ledge.

I actually measured it again today and it's only 2.5m rather than 3 so it's a bit easier! Part of the need for the depth is the roof is slopping so then 20/30cm closest to the garage door is almost entirely useless.

Do they make 80cm deep twin slot shelving brackets? That would work if they did, though it puts a lot of the weight through a small bit of wood.

I'll try and post an image of the space later today.

 

[webbier]

Here it is. I'm basically trying to make a loft storage space. The metal bits holding the roof down are 80cm out of the door.

 

[Sachakins]

OK, get it now. Twin slot biggest I've seen is 610mm, so maybe not the best method.

I think two joist hangers each end, 2 2x4, then make shelf about 500 deep, with a back edge of 3/4 ply, screwed to shelf back about 4" or so tall. This will prevent anything getting pushed of the back and help prevent shelf bowing.

 

[Stanleymonkey]

Do you still drive the car into the garage?

Or do you just use the door for access / bikes / lawnmower etc?

If the car never goes in - you could support from below. Even build some shelving half way across and use that to support most of the over door shelf.

 

[Jameshow]

OK, get it now. Twin slot biggest I've seen is 610mm, so maybe not the best method.

I think two joist hangers each end, 2 2x4, then make shelf about 500 deep, with a back edge of 3/4 ply, screwed to shelf back about 4" or so tall. This will prevent anything getting pushed of the back and help prevent shelf bowing.

Or you could make it 1000mm deep using 18mm ply and a 200mm back wall to stop anything falling off the back?

4x2 under the front edge. 4x2 into wall to rest it on.

 

[webbier]

We don't own a car and the garage was built when cars are much smaller than they are now, we'd have to exit the car through the sunroof! That said keeping the doorway clear is useful as we have a bike trailer for our child and it does need space to maneuver to swap it between our bikes etc...


Ah ok, so th shelf is screwed on vertically to the end nearest the door and works as both a lip for the shelf and an edge support for the 2 x 4. That's good. If I have understood correctly with that design nothing would be attached to the existing beam above that you can see in the video?