Losing Pea Gravel from underneath small footer for greenhouse
#1
10-13-14, 11:09 AM
Losing Pea Gravel from underneath small footer for greenhouse
We poured a small footer (9" wide and 4" deep) for a greenhouse to tie the bottom plates of the walls to. After removing the forms and in the process of all the pounding from the framing the pea gravel is falling out from under the concrete. Is this going to be a problem in the long run? If its not obvious, this is my first time doing something like this.
#2
10-13-14, 02:16 PM
Depending on how much is coming out and how long the wall is this could definitely be a problem. Pea gravel is the raw material to use for this application because it doesn't compact. Post some pictures of what you've got.
#3
10-14-14, 06:20 AM
Thanks for the quick reply Msradell. The footer is 12' X 8' and there is expansion material roughly no more than every 6'. I'll take some pictures after we pump out the water - we just got 3"+ inches of rain so we've got a swimming pool going inside the footers. It's always something 
#4
10-14-14, 06:51 AM
Group Moderator
Typically you would back fill around the footer which would prevent the gravel from coming out. The sooner you can backfill the better to prevent more stones from coming out as it's undermining your footer.
#5
10-14-14, 07:57 AM
Yeah, I should have done that - at least one the outside. The problem on the inside is that I'm going to add stone for a heat sink so I've dug out there. I'm considering lining the inside of the footers with some extruded insulation panels - that would keep the pea contained and help insulate the inside of the greenhouse. Is that a good idea? If so, I can replace the pea from the outside of the footers then backfill?
#6
10-14-14, 09:09 AM
Group Moderator
You can not disturb or allow the pea gravel under the footer to be disturbed or removed. Any movement of that stone undermines the footer. You cannot "put back" stones under a footer and have the same strength. Consideration of that must be taken during construction and before the pour like installing your foam panels on the side before the gravel was installed and concrete poured. Pea gravel is especially bad because it's rounded shape allows it to easily flow and pour out of any opening. Crushed stone with it's jagged irregular shape tends to stay in place better and does not need quite as much care keeping it contained.
