[cmj]

Hi guys,

I have a garage that only has 3 joist along a 17' width and I would like to add one joist for every rafter. What are the trade offs between resting the joists on the beam and nailing them to the rafters or using hangers and attaching them to the face of the beam? I would rather use the hangers as the joist would be lower.

Thanks.

 

[Just Bill]

Not sure I understand what you have or why you want to make additions. Are rafters stick built or truss, spacing, size, purpose for making changes???

 

[cmj]

The garage is stick built 17'x20'. The rafters have 16" spacing. There are currently 3 joists running the 20' span and they are 2x4, there is also 1x6 planks that form an X connecting the corners. I just want to close off the ceiling using 2x6 or 2x8 joists every 16", I don't intend to store any substantial weight up there. I know I can fit a 2x6 joist to the 2x4 rafter by resting the joist on the beam and nailing it to the rafter. I don't think it is possible to fit a 2x8 in the same place, but if I use a joist hanger I could get the joist lower allowing more room for the 2x8.

I know that 2x6 joist spanning 20' are not advisable but they should be much better than the 2x4s that have been there for the last 50 years.

 

[Wildie]

The garage is stick built 17'x20'. The rafters have 16" spacing. There are currently 3 joists running the 20' span and they are 2x4, there is also 1x6 planks that form an X connecting the corners. I just want to close off the ceiling using 2x6 or 2x8 joists every 16", I don't intend to store any substantial weight up there. I know I can fit a 2x6 joist to the 2x4 rafter by resting the joist on the beam and nailing it to the rafter. I don't think it is possible to fit a 2x8 in the same place, but if I use a joist hanger I could get the joist lower allowing more room for the 2x8.

I know that 2x6 joist spanning 20' are not advisable but they should be much better than the 2x4s that have been there for the last 50 years.

For the record, those 2X4's that you have running across are called 'collar ties'. Their function is to keep the walls from being pushed out from the weight of the roof!

You could consider making a truss from the rafter and its mating joist (collar tie) then the sheeting weight would be carried by the roof!
Remember 2X8's are twice as heavy as 2X4's, and add to the load!

 

[cmj]

I thought collar ties were up higher. In my garage there are also a few collar ties connecting the rafters about half way up from the top of the walls to the peak.

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[Wildie]

I thought collar ties were up higher. In my garage there are also a few collar ties connecting the rafters about half way up from the top of the walls to the peak.

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So when do ceiling joists become collar ties and vise versus? Good question!
Collar ties are used to keep the rafters from being spread as the weight of the roof press's downwards.
They can be placed at any height, from the rim plate to the ridge!
When a ceiling or floor is to be installed over-head, then joist would be a proper description.
Confusin' aint it! (grin)

 

[Maintenance 6]

I agree with Wildie. They are ties. If all you want to do is close off the ceiling, why not just place more 2x4s and tie wire them to the rafters/ then apply your ceiling to the 2x4s. That would be the minimum in weight, materials and expense.

 

[cmj]

That is an option. But that leads back to this question: Is it ok to attach the 2X4s to the face of the wall rim/beam with hangers instead of sitting them on the rim and nailing them to the rafters?

Right now the X brace is in the way and it woud be easier to hang them just below it.

 

[Maintenance 6]

I wouldn't see why you couldn't.

 

[Greg24k]

That is an option. But that leads back to this question: Is it ok to attach the 2X4s to the face of the wall rim/beam with hangers instead of sitting them on the rim and nailing them to the rafters?

Right now the X brace is in the way and it woud be easier to hang them just below it.

Put beams across resting them on the top plates. If you using 2x8 cut the ears off to clear the plywood and to make them fit nice and snug against the rafter and fasten them to existing rafters and the top plate. Put 2 rows of strong backs 6 feet from each side (2 x6 nailed across ceiling joists flat with a 2X4 nailed to the side of it on the rib side) and hang your sheetrock. If anything in the garage adjacent to the living space be sure to confirm to fire-rating requirement in your state.

Good luck :thumbsup:

 

[cmj]

Thats the kind of answer I was looking for, thank you.

I was not sure if I could fit a 2x8 next to a 2x4 rafter.

 

[wombosi]

my garage is the same way. i recently added a 2X12 to hang some exercise equipment from.

if all you want to do is put up a drywall ceiling, then 2X4's are fine for "joists," as long as they each have a vertical piece in the center going up to the rafter or ridge.

if you plan on storing anything up there, or want to be able to walk around up there, you'll need at least 2X12s. they are tricky to put up on the top plate, but doable.

if you want to drop your ceiling, just nail the joists to the studs, then add a 2X4 ledger underneath them all.

i probably would not go with 2X4, even if it were just for drywall.

my garage is 20' wide, and even the 2X12 has a lot of spring and wobble over that span, and that's WITH a 2X6 in the center going up vertically.

 

[Dell]

schmolze, et al.,

How were you able to squeeze the 2" x 12" up above the top plate with the roof on? I have a 20' x 20' garage that has a single 2" x 6" joist and two collar ties - that's it. I'd like to add 2" x 12" joists (with kings posts or strong backs to help) but I don't see that I would have much material sitting on the top plate of the wall once I cut down the the 2" x 12" enough to get it to fit. The rafters are spaced 16" apart.

Anyone know of a trick to get those 2" x 12" in place?

Thanks,
Dell.

 

[Greg24k]

Cut the ears off on 2 X 12 (the ends on 2X to follow the roof contour) to get 3 1/2" sit on the plate and nail to the roof rafter and the plate

schmolze, et al.,

How were you able to squeeze the 2" x 12" up above the top plate with the roof on? I have a 20' x 20' garage that has a single 2" x 6" joist and two collar ties - that's it. I'd like to add 2" x 12" joists (with kings posts or strong backs to help) but I don't see that I would have much material sitting on the top plate of the wall once I cut down the the 2" x 12" enough to get it to fit. The rafters are spaced 16" apart.

Anyone know of a trick to get those 2" x 12" in place?

Thanks,
Dell.