I'd like to add some storage space in the ceiling of the garage. It looks like someone got a start on it already. There looks like a 16 foot 2x4 nailed into the top of the wall on both sides with one 2x4 spanning. If I put more 2x4s across the span every four feet, is that going to hold a plywood subfloor and some light storage

Left Side


Right Side

View 2

View 3

  • 1
    That 2x4 is more to hold the bottoms in place when building. Some plywood will not hurt, but the main thing is LIGHT storage. Those trusses are not built to hold weight.
    – crip659
    Sep 16, 2023 at 20:29
  • @crip659 Is there any way to reinforce the tursses?
    – Chad
    Sep 16, 2023 at 21:21
  • I should have said heavy weight. It also depends on how the weight is spread out. Usually it is pounds per square foot. 200 pounds over 20 square feet is much better than 200 pounds on 2 square feet.
    – crip659
    Sep 16, 2023 at 21:39
  • @Chad can you provide a better "lengthwise" picture of this space showing the trusses?
    – Ecnerwal
    Sep 16, 2023 at 21:44
  • 1
    @Ecnerwal I added two more images
    – Chad
    Sep 16, 2023 at 22:30

1 Answer 1


Ideally, you find out who made your trusses and get the specs from them for exactly what they were designed for. That information may be in plans which may be on file at your LAHJ or there may be information stapled to or written on to the face of one of the trusses.

These pictures make it hard to tell, but there's some chance it's actually a "spare room" or "attic" truss with potential weight-holding capacity designed in. The apparently open center and relatively heavy bottom chord suggest that.

Attic truss picture

Image source https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fswifttimber.co.uk%2Fuploads%2Fimages%2Ftrussed-roofing%2Ftruss-attic.png&f=1&nofb=1&ipt=98a0dd23d6fd60eb00cd9803978a0127208028a67186b104779b8fbabd91fc65&ipo=images no endorsement implied

Your new pictures make it quite clear that's exactly what you have for a truss, and as such, it should take reasonable loads (still would be ideal to track it down and find out what it's designed for,) but this is not "just rafter ties" nor is it a truss that's only intended to support the roof and a ceiling below. Truss spacing appears to be 24" on center, so 3/4" ply/OSB (T&G preferred) should be floor-span-rated for that spacing directly, no extra 2x4's needed.

When you have half the floor sheathed and properly connected to the chords, you can remove the "rat-board" 2x4 down the middle and keep going to the other side, since all that is doing is holding the bottoms of the trusses, which the floor will do once it's in place.

  • The mending plate on the chord would concern me.
    – Mattman944
    Sep 17, 2023 at 2:21
  • @Mattman944 that's a very normal part of engineered truss manufacturing. Not a field repair, and nothing to be concerned about.
    – Ecnerwal
    Sep 17, 2023 at 13:43

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