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| Bowed Floors [message #315487] |
Tue, 04 April 2017 23:51  |
Paul
Messages: 12
Registered: December 2014
Location: Lynnwood WA
Karma: 1
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Junior Member |
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Hi again. Another problem to solve. My floors sag at the edges and bow up in the middle. My wood floor at the entrance floats about a half inch over that structural member at the bottom of the body, where I believe the wood is supposed to touch. The middle aluminum floor joist (about 3 ft behind the steps) also sags noticeably from the frame to where it bolts to the body.
I kind of hid the problem by bolting that joist down to the frame cross-member directly beneath it. It kind of sucked the floor down flat, but it still sags at the edges. So I certainly don't like the solution. And while I have the interior gutted, I would like to apply a better solution.
I read about one guy who braced up the outer edges by bolting a brace to the outside of the frame. But even that's a bit awkward, dodging the parking brake cable. And I'm not equipped to fabricate my own brace.
So my first question is, can I replace the wood flooring by simply unscrewing those heavy aluminum strips on each side, that appear to hold down the wood floor? Do I understand correctly that it is the aluminum joists that support the body on the frame, and not the wood floors? (IOW, can I remove the wood floors without lifting the body off the frame?) Then if I get the wood out, why shouldn't I add some hefty angle-aluminum, back to back, to act as more floor joists, and bolt them to the bottom of the body, to assist the existing joists? Then fill between them with narrower wood flooring.
Thank you again to all willing to share your knowledge and experience.
Paul
Paul & Carolynn Lynnwood WA
'73 23' I don't know the model. Mid-bath.
Presently gutted. Installed One-Ton FrontEnd.
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| Re: Bowed Floors [message #315488 is a reply to message #315487] |
Wed, 05 April 2017 00:27  |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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Senior Member |
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Since you have it gutted, you probably can hold up the body shell with just those aluminum frames, as long as you don't have any other excess weight up top. I would still brace it up with some type of stands so Murphy isn't tempted to invade your scene.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: [GMCnet] Bowed Floors [message #315583 is a reply to message #315541] |
Thu, 06 April 2017 22:01 |
Paul
Messages: 12
Registered: December 2014
Location: Lynnwood WA
Karma: 1
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Junior Member |
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Justin,
Thanks especially for the picture. That is the best closest picture I've seen with the wood floors out. And I appreciated your articles on your website. I will come back to that and read more.
My intention is to leave the floors in from the wheel wells back. I think the flooring there is in good enough condition, I don't see any sagging problems, and I have already re-placed the original wet-bath back in place.
But you give me some courage to make the move to remove the two panels (on my 23') ahead of the wheels.
No one commented on beefing up the cross-members (I called them floor joists, for want of a better word), that I saw. But if I manage to remove the floors, I will do what I have to to support the floor and the body.
Paul & Carolynn Lynnwood WA
'73 23' I don't know the model. Mid-bath.
Presently gutted. Installed One-Ton FrontEnd.
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| Re: [GMCnet] Bowed Floors [message #315588 is a reply to message #315583] |
Fri, 07 April 2017 06:27 |
Richard Denney
Messages: 920
Registered: April 2010
Karma: 9
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Senior Member |
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Paul, I have the same problem on mine, but have not yet been motivated to
do anything about it. The aluminum top-hat-section floor beams creep over
time, and the plywood of course creeps with it. There is not vertical room
for a stronger (as in, deeper) crossing beam, and support from the frame
needs a vibration pad like the rest of the body.
We used to call it "middle-aged spread" and assume that the body itself was
widening. That's probably happening, too. And we used to blame wrinkles in
the lower body panels on the breakdown of body pads, but I suspect in my
case it is caused by the mustache shape the floor base taken in section.
I seem to recall from the deep past that Marsh Wilkes (who, like me, seems
to be poking in from time to time of late) was constructing an aluminum
floor structure that replaced the plywood altogether. I don't know how that
turned out.
But sag is inevitable without that support from the frame. The body is
supported 10-12" inboard of the edge of the body, and so the weight of the
walls plus all that is attached to them is cantilevered out from the frame.
With only 1-1/2" or 2" of distance between the top of the frame and the top
of the floor, there isn't much depth for a structure to resist that offset
load forever.
Getting the plywood to unsag by replacement should also include
straightening those aluminum crossing beams. But I wouldn't expect that to
last without some additional support.
Rick "still ignoring this problem for now" Denney
On Thu, Apr 6, 2017 at 10:02 PM Paul Sager wrote:
> Justin,
>
> Thanks especially for the picture. That is the best closest picture I've
> seen with the wood floors out. And I appreciated your articles on your
>
> website. I will come back to that and read more.
>
>
>
> My intention is to leave the floors in from the wheel wells back. I think
> the flooring there is in good enough condition, I don't see any sagging
>
> problems, and I have already re-placed the original wet-bath back in place.
>
> But you give me some courage to make the move to remove the two panels (on
> my 23') ahead of the wheels.
>
>
>
> No one commented on beefing up the cross-members (I called them floor
> joists, for want of a better word), that I saw. But if I manage to remove
> the
>
> floors, I will do what I have to to support the floor and the body.
>
> --
>
> Paul & Carolynn Lynnwood WA
>
> '73 23' I don't know the model. Mid-bath.
>
> Presently gutted. Installed One-Ton FrontEnd.
>
>
>
>
>
> _______________________________________________
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> GMCnet mailing list
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| Re: [GMCnet] Bowed Floors [message #315597 is a reply to message #315588] |
Fri, 07 April 2017 10:21 |
Hal StClair
Messages: 971
Registered: March 2013
Location: Rio Rancho NM
Karma: -12
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Senior Member |
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You could give it a slight body lift and straighten it out. Add a pair of angles to each cross member bolted to the aluminum cross members. You might need to bend the member before bolting the new re enforced angles to them but with everything out as you now have it, it shouldn't be a very tough job. Probably do it with 1/4" angle witch wouldn't be noticed.
Just thinking out loud.
Hal
"I enjoy talking to you. Your mind appeals to me. It resembles my own mind, except you happen to be insane."
1977 Royale 101348,
1977 Royale 101586, Diesel powered,
1974 Eagle Bus 45',w/slideout,
Rio Rancho, NM
[Updated on: Fri, 07 April 2017 10:22] Report message to a moderator |
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| Re: [GMCnet] Bowed Floors [message #315642 is a reply to message #315597] |
Sat, 08 April 2017 13:06 |
Paul
Messages: 12
Registered: December 2014
Location: Lynnwood WA
Karma: 1
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Junior Member |
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I looked up some pictures by Marsh Wilkes. He went all out with the all-aluminum floor. Although it doesn't appear that he addressed what seems to me to be a structural weakness, that the entire body is supported by those few shallow cross-members that cantilever out over the frame. By my measurements -- correct me if I'm wrong -- those are only around 5/8" deep.
So yes, since we cannot add depth, it seems I need to add more cross-member supports, to lift the body back up, and flatten my floor out. Thus I am presently picturing combinations of angle- and channel- aluminum, spread evenly between the existing supports (and padded over the frame, as I replace the existing pads).
I don't yet know how many more I want to add. I am wondering if the aluminum is that much more expensive than the marine plywood. Can anyone confirm, how thick of plywood will I be looking for?
I don't yet have a clear picture of how these supports connect to the body. Although from one picture, it looks like there is a channel in the body structure that they fit into. I assume this will become clear as I get the existing wood out.
And perhaps I may have to also add some L-braces to the outside of the frame, under the existing cross-members, to get them straight. Although if I have to do that anyway, one might question whether my idea to add the supports all the way across is even necessary. So clearly I am going to still make some decisions as I go.
Now I need to find some time. And money. And I need it to stop raining. (This is all being done outside)
Paul & Carolynn Lynnwood WA
'73 23' I don't know the model. Mid-bath.
Presently gutted. Installed One-Ton FrontEnd.
[Updated on: Sat, 08 April 2017 14:06] Report message to a moderator |
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| Re: [GMCnet] Bowed Floors [message #315676 is a reply to message #315642] |
Sat, 08 April 2017 20:00 |
midlf
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
Karma: 1
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Senior Member |
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Paul - '73 floor is one inch plywood.
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
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| Re: Bowed Floors [message #315729 is a reply to message #315487] |
Sun, 09 April 2017 10:56 |
Handyman
Messages: 229
Registered: April 2016
Location: The Netherlands
Karma: 2
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Senior Member |
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Just a thought.
Is it not possible to use a "sandwich floorplate"
Underside polyestherplate then insulation and on top marine quality plywood, all three bonded by the insulation.
This becomes very solid flooring, with the extra advantage, underside is fully waterproof, insulated and the top can be used to screw and/or glue stuff on.
I don't realy know what kind and variations are available in the USA, but here in Europe there are many available, used in Motorhome builing.
I am sure there will be more knowledgeable people here, for US sources.
Daniel
PS I once made my own piece for repairing a floor in an older RV. Used PUR Foam, almost non-expanding, then fixation them , so the thickniss was what I wanted, I did work out very well. But then is was only a little piece I needed, less the 3 by 3 feet.
Daniel Jacobs, NL-USA 1977 GMC Eleganza II, Rebuild 455 (2019) 3.55 FD. FiTech and (Modified) FCC, Electric Pump, insulated GasTanks, 100A Alternator, APC, McDash, Schräder Valves + extern Fills, Ceramic Film, TPMS, FlexSteel Seats
[Updated on: Sun, 09 April 2017 11:57] Report message to a moderator |
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