Hello all. I have a root cellar/bunker in my backyard. Walls are cinder block and ceiling is tongue and groove board and then concrete above that. The boards are mostly rotted and mold stricken. My question is if those boards are structural or not. The room is 12x12 with a height of 8 feet. Thanks for any advice!!!
1960 root cellar concrete ceiling
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Whether or not the boards were structural way back when, they are structural now because the concrete was poured on top of them.
Put up temporary joists paralleling the existing joists then tear down a strip of old ceiling at a time between two joists. Replace with new permanent joists. with short subfloor planks spanning two new joists at a time center to center.
I would anticipate that, due to the weight of the concrete, the new joists would have to be put at less than 16 inch centers. Consult the International Building Code or similar code book used by your city to figure out the joist size and quantity needed to meet the pounds per squre foot floor loading for new framing plus the weight of the concrete given the latter's thickness.
You might also need a center beam where none was before, to support the weight of the concrete and to better install half length new joists where a full length joist could not be wiggled into place between the walls.
Was this room converted to a fallout shelter at some earlier date to justify the concrete on top?
Put up temporary joists paralleling the existing joists then tear down a strip of old ceiling at a time between two joists. Replace with new permanent joists. with short subfloor planks spanning two new joists at a time center to center.
I would anticipate that, due to the weight of the concrete, the new joists would have to be put at less than 16 inch centers. Consult the International Building Code or similar code book used by your city to figure out the joist size and quantity needed to meet the pounds per squre foot floor loading for new framing plus the weight of the concrete given the latter's thickness.
You might also need a center beam where none was before, to support the weight of the concrete and to better install half length new joists where a full length joist could not be wiggled into place between the walls.
Was this room converted to a fallout shelter at some earlier date to justify the concrete on top?
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Are there joists or just tongue and groove boards? You didn’t mention joists so my comments assume there are none. Tongue and groove boards spanning 12 feet under a concrete slab without framing are not supporting anything. The boards were probably used as a forming material. They would have put the boards in place with shoring beneath them, placed the concrete and the after it cured the shoring was removed. That would make it a structural slab. Now, many years later and not knowing details about the concrete, it could need some support. Please post whether there is framing or just boards.
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Ayuh,...... Duplicate thread,.....
I agree with Thomas,..... Rip 'em down, 'n start over with whatever ya want,.....
I agree with Thomas,..... Rip 'em down, 'n start over with whatever ya want,.....
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16,362 Posts
When a board is removed is there a gap between the ceiling and the wall?
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16,362 Posts
As each T&G board is removed replace it with tapered cedar shims or equivalent and it'll probably be good for another 60 years.
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72,240 Posts
So no detail on concrete used or rebar in it?
There was a farm up here didn't know they had one until they had a sink hole in the yard.
You might be able to use a metal detector to verify rebar in the concrete. Or have someone with a ground penetrating radar do a mapping.
If the concrete is reinforced then all you would need to do is put blocks here and there between the I-beams and the concrete ceiling, and you are done and golden.
High school industrial arts problem requiring some math. Given a door to the basement and a door or window to the upstairs not too far away, compute the thickness of the concrete floor.
If the concrete is reinforced then all you would need to do is put blocks here and there between the I-beams and the concrete ceiling, and you are done and golden.
High school industrial arts problem requiring some math. Given a door to the basement and a door or window to the upstairs not too far away, compute the thickness of the concrete floor.
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We have a White metal detector and locating re-bar in our 9" concrete basement ceiling is the only thing it's worth taking out of the box for.
EDIT: EDIT:
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Remove the old wood and replace with pressure treated wood.
You might want to put some roofing paper between the new wood and the concrete for added assurance or even some 6 mil plastic.
Save the old wood, plane it down, send it to NYC as repurposed wood and sell tf for the cost of a new car. They'll buy anything old up there.
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I would not be concerned about removing wood, my concern is the overall strength of the structure.
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