Hoist hung from attic trusses?

[joe1086]

We ordered a free standing cast stone tub that weighs about 400 lbs for an upstairs bath. I need to put it in place for rough in measurements, then move it out of the way, and eventully lower onto a floor drain. 

Was thinking of installing a one ton HF hoist over the tub location. Plan would be to get in the attic, lay a 2x6 across two, potentially three, of the bottom truss chords. Then I could attach an eyebolt from the bathroom through the 2x6. A hoist, a couple of straps, and two dollies would make it pretty easy to pick up and move this beast around.

The tub location is near the corner of the house, so the weight would be within three feet of two load bearing walls.  The weight on the trusses woud be temporary, probably twice for 10 or 15 minutes each.

Am I asking for trouble?

[Bob10]

We ordered a free standing cast stone tub that weighs about 400 lbs for an upstairs bath. I need to put it in place for rough in measurements, then move it out of the way, and eventully lower onto a floor drain. 

Was thinking of installing a one ton HF hoist over the tub location. Plan would be to get in the attic, lay a 2x6 across two, potentially three,  the bottom truss chords. Then I could attach an eyebolt from the bathroom through the 2x6. A hoist, a couple of straps, and two dollies would make it pretty easy to pick up and move this beast around.

The tub location is near the corner of the house, so the weight would be within three feet of two load bearing walls.  The weight on the trusses woud be temporary, probably twice for 10 or 15 minutes each.

Am I asking for trouble?

Not sure what is in your attic but I could tell you what I would do.  If possible use a dolly if not support the ceiling from inside the room with x2 from the floor up.  While the load while is close on one side i would shorten the span to the next support

[Roly]

Not sure what is in your attic but I could tell you what I would do.  If possible use a dolly if not support the ceiling from inside the room with x2 from the floor up.  While the load while is close on one side i would shorten the span to the next support

What size lumber is the truss made of ?   If these are 2x4s  I would not trust them.   Could you sister 2x6s to the truss from wall support to wall support so you are not loading the trusses if they are the type made just for a ceiling load.  Roly

[joe1086]

Not sure what is in your attic but I could tell you what I would do.  If possible use a dolly if not support the ceiling from inside the room with x2 from the floor up.  While the load while is close on one side i would shorten the span to the next support

Hmmm...that might be easier. I could fashion a bridge inside the bathroom with 2x4 studs with a 2x6 header. All work would be done in the bathroom and I'd avoid having to go in the attic. Nothing up there but blown insulation.

[joe1086]

What size lumber is the truss made of ?   If these are 2x4s  I would not trust them.   Could you sister 2x6s to the truss from wall support to wall support so you are not loading the trusses if they are the type made just for a ceiling load.  Roly

Roly they are 2x4 trusses, 24 inch OC.

[Roly]

Hmmm...that might be easier. I could fashion a bridge inside the bathroom with 2x4 studs with a 2x6 header. All work would be done in the bathroom and I'd avoid having to go in the attic. Nothing up there but blown insulation.

Sounds like the best plan if you have room to do it.   If you are using slings on the tub use spreaders so it does not crush the sides.  Roly

[Splinter Puller]

When I built my shop the trusses I ordered had about 10 lbs per square foot bottom chord loading and full snow loads for the top chords.  I wanted a hoist so I took (2) 2x12's and stuck them in the joists space perpendicular to the trusses.  The 2x12's span about 7 trusses and are attached to both the top and bottom chords of the trusses with 2x blocking.   From the middle of the 2x12's I used large U bolts to secure a Steel hook at the ceiling below the trusses.  On this hook I hung a winch.    I calculated the weight in insulation and drywall of my ceiling and subtracted this from the load capacity of the 7 trusses bottom cords and I have a margin of about 1000 lbs.  Because my 2x12's are supported also by the top chords I figure I have about 3000 lbs of safety factor... especially if there is no snow on the roof.  My winch is 1000 rated so that is my limit.    I've tested the hook by using multiple come-a longs to lift my 2 ton bobcat and with half it's weight off the ground there was no measured deflection on the roof.

So.. to summarize, spread the loads far enough and you should be fine.  Even do the match.   Most roof trusses are stamped with their top and bottom chord load limits.

[petertay15]

How much hot water will it take to warm up 400 pounds of stone? Hope you can get a warm bath!

[joe1086]

How much hot water will it take to warm up 400 pounds of stone? Hope you can get a warm bath!

You're likely right about that, but not too worried about it as the tub in the master bathroom has seen water in it only about 25 times total in 27 years. I thought about not even putting a tub in the room with this redo - but we're going this route to avoid resale issues down the road. Bigger concern is once it's delivered getting it from the garage and up one flight of stairs. Probably going to hire out for that.

[crokett™]

I would think you could rig an engine hoist to hold the tub. The engine hoist is also on wheels so could roll the tub around.