Strapping The Ceiling

Howdy, y'all. I'm putting up straps in an attic of an early 1800s house with 32 inches between the rafters. What options might I have for strapping that won't sag between the beams? 1x3 but 12 inch on center? Or do I need to use stronger materials?

Hello James,
I know of no "span tables" for 1x material on the flat. (There is a lot of forum discussion on 1x3 and 1x4s used on the edge as joists in model train table building.)

32 inches is a long way to go so I think you could be wise to use the 1x4 and 12" on centre. Probably most important is the straightness and lack of twist to the boards, and absence of large knots. How much weight you are putting on the ceiling could be important as well. An additional note is to never use water resistant drywall on any ceiling, it will always sag because of the wax in the gypsum mixture.
Jon

Hi, I’m starting a cabin 24x28 ceiling and want to use screws . What length/type screws to use to attach the 1x3 strapping to the over head trusses.
Thanks for any assistance or information,

Hello Mary,
Screws should go at least 3/4" into the structure. with 3/4" strapping you will need at least #8 1-1/2" screws. If you are using heavier drywall, like for soundproofing, you may want 1-3/4" or 2" screws for the strapping. For attaching drywall to the strapping - never more than 3/4" into the strapping to avoid nail popping. See the "Nail Popping" video in the list of videos.
Jon

Hi, I’m starting a cabin 24x28 ceiling and want to use screws . What length/type screws to use to attach the 1x3 strapping to the over head trusses.
Thanks for any assistance or information,

Hello Mary,
Screws should go at least 3/4" into the structure. with 3/4" strapping you will need at least #8 1-1/2" screws. If you are using heavier drywall, like for soundproofing, you may want 1-3/4" or 2" screws for the strapping. For attaching drywall to the strapping - never more than 3/4" into the strapping to avoid nail popping. See the "Nail Popping" video in the list of videos.
Jon

Iam put up 5/8 drywall in my garage on a old ceiling, That i do not to take down Should i use strapping or screw it to the old ceiling Thanks for any information,Jon

Hello Mike,

Your screws need to mechanically fix to the joists, not the old ceiling material. Strapping allows for long wood screws through an existing ceiling into the joists, be that wood or even a combination of wood and insulation. Then shorter drywall screws through the 5/8 drywall into the strapping.

If you use very long screws to hold the drywall, you have to very careful to drive them just flush (really had to do with 3" screws), and use Philips screws as you find on all drywall screws, because square socket Robertson screws will spit back out the drywall compound.

Hope that helps,
Jon

Do you need to nail or screw the end of the strapping to something ? Do you need to add blocking to the end somehow?

Hello Clarke
Whenever fastening near the end of softwood, especially thin strapping, you should drill a pilot hole for either a nail or a screw as without a pilot hole it will very likely split a 1x2 even a 1x3. Several inches from the end it should be ok.

jon

Thank you for the very clear explanation!

can I use 2x4's for strapping

Hello Jim,
Sure - but why spend the money and loose the headroom?
-- Jon

Hello Doug,

According to the CGC handbook - when drywall is placed parallel to the strapping, the strapping must be on 16" centres, when placed perpendicular to the strapping it can go to 24" centres -- but this is not recommended if water based texturing material (like stucco) is to be applied. 

When applying texturing materials, it is a good idea to use Sag Resitant drywall panels.

1-1/4" penetration into the wood -- hence with 3/4" strapping, a minimum of 2" long screws.  If you are using very dry 1x3s for the strapping it would be wise to pre-drill through the strapping to avoid splitting.

How far apart can ceiling joists be to support 1/2 drywall without sagging?

Jon I am starting a gareage ceiling, and want to use screws. What length/type screws to use to attach the 1x3 strapping to the overhead trusses?Thanks for any information,Jim