supporting pipes

ChrisJ

I'm really not happy with how my steam mains are supported near the boiler.

My floor joists like to move A LOT, which is a while other issue I may or may not fix in the future as there is little headroom even now.



I constantly watch the straps move on the mains when people walk and of course I get noise from this and I'm sure the boiler doesn't care for it.  My idea is to jam a piece of 3/4" iron pipe in between my header and concrete floor as a support and loose the straps near the boiler.  I would of course cut in a wooden dowel to keep the pipe from crushing my insulation.



Will this work?  Is the placement ideal?  Does it even matter?

Boiler Talk

supporting pipes

I'm not the expert, but for every action there is an equal and opposite reaction.  I think your better off strenghtening the floor above.  One of my pipes is tied horizontally, but the floor doesn't move much.  I think it was tied years ago because it swayed under operation.  Perhaps you worry too much.  The old pipes didn't get hurt, right?

You could sister the joists above with new joists or perhaps cut 3/8" or 1/2" plywood to fit on the weaker joists and glue and screw them on.   Strenghtening the joists doesn't reduce head room. 

icesailor

Strength:

Sister the joists with Glue-Lams and be done with it. The best way to take the bounce out of a bouncy floor.

Don't even consider making the heating system part of the structural integrity of the building.

ChrisJ

What?

I never said anything about using the steam mains to strengthen the floor.

I want the end of the mains and header to be supported from the basement floor so movement in the  upstairs floor doesn't effect them.  I essentially want to isolate them from the wood floor above near the boiler.  Of course the rest of the mains will be suspended from the floor, but this is all near the foundation so there is barely any movement.



As I said, beefing up the floor is a whole separate issue. 

As far as strengthening the joists, in my opinion sistering a joist next to it of the same size will not increase strength enough, the best option would be to run a beam across them and support them with lolicolumns.  This would not only be far easier and cheaper, it would cut the span in half greatly reducing bounce.

Danny Scully

While this may be...

While this may be unconventional, it's seem like you're set on not using the floor joists for a means of supporting the header. I would say using 3/4 or 1" iron pipe like you were thinking, but put a termination flange on the floor and then a split ring hanger on top over the header. Size the split ring hanger to go over the insulation, this way it wont damage the insulation and at the same time it will allow for any movement of the header.

jumper

just make certain

just make certain that you have an adequate foundation for those columns. Ideally pipes move with no harm. After all they expand & contract regularly.

Hap_Hazzard

Use real pipe hangers.

Do whatever you need to do to stabilize the floor first. I agree with the Glu-Lam recommendation. Then you'll have something solid to hang your pipes from. The PDF I'm attaching should be useful in determining the size and spacing of hangers. You should use hangers that are designed for this purpose. Perforated straps are not good enough.

ChrisJ

ok

I see that everyone seems to agree on strengthening the floor first.



I'll see what I can do, however it doesn't look like it will be happening for quite a while due to fundage.



As others may remember, I have a water pipe that should be dug up and replaced as well.

ChrisJ

You guys are killing me

Ok so i just talked to my dad (carpenter for 40 years) and he said he will come down one day and help me work on the floor.



He claims, it won't cost much or take long to make things right, so I guess we'll see.

After that I will buy the proper pipe hangers as recommended.



The only reason I went with the straps in the first place is that was what was here already, so I figured it was appropriate. I guess it was more like what was cheap, than proper.





Thanks for your time.

Polycarp

strength

If your house is old enough to have steam heat, then those joists were almost certainly plenty deep when they were installed.  Most likely, the problem isn't that the joists weren't big enough, but that their structural integrity has decreased.  Sistering them should give you all the structural stability you need, especially if you use glulams.



A beam and posts certainly would do the job, and probably do it better, but that could be serious overkill.  You're losing head height to the beam, which may or may not be a big deal to you.  You have to invest in the columns.  But most importantly, you have to add footers for those columns.  Whether or not the floor can take the new loads, code isn't going to let you change the structural system like that and add columns without footings.  If you have concrete floors, that means cutting holes in the slab, digging and pouring the footing.  That is not inconsiderable.  Just things to consider.  If you already have pipes or wires running through your joists, sistering them can be a major pain too.



Since fixing the floor is a whole other issue, you might just consider sistering the joists above your boiler to take some of the bounce out of the part of the floor above that rigid connection to your boiler.  If it is only temporary until you can take care of your floor the way you want, you could shift your idea just slightly.  Install a lolly column or post to support the joist adjacent to your boiler and then support the main from that joist with a real main support.  This will give the floor some rigidity without creating a weird support structure for the main.

ChrisJ

strength

The house was built sometime in 1874 or before. Steam heat was added in the 1920s.



As far as the joists being strong enough, I have 2x8s 24" on center over a 16 foot span. Sure, they work but they certainly move.

Polycarp

Wow

That's impressive. We're talking an era when 2x8s (actual 2x8s, not nominal dimensions) of oldgrowth on 12-16" centers were the norm. 24" OC is surprising .. though certainly not unbelievable.



If you have 24" spans for the subfloor, I wouldn't sister the joists. I'd install the new joists in the middle between the originals. Some of your bounce is due not just to the joists, but to the floor itself flexing (even if you only care about the impact on the boiler right now, taking out the flex is a good thing too.) If it's still just all nails I bet you have some serious squeaks. Taking the span to 12" would make a huge difference. You should check some rules of thumb to see what the depth of those joists should be for your span. I bet you'll find that for 16', you should have 10" joists.



Happy structuring.