drain tile

[tobilennon]

hi, I've a question: when you discover that the foundation wall has no footing, and you trying to install a drain tile system (interior), what's the best option to keep the wall up, while u digging the trench. and how to secure the walls in place without falling.

tx.

[waynesoper]

I would be resupporting the entire wall from the inside and planning on installing a proper foundation wall WITH a footing. Why would you go to all the trouble of digging it all up and not fixing it right?

[hausdok]

Have your contractor add a footer under the wall 4ft. at a time skipping every other 4ft. section. Make sure the contractor uses dobies and #4 rebar to reinforce the new footer and extends the rebar into the earth at either end of the footing excavations so that when the area between the first set of new footers is excavated there will be something to tie into. Use Form-a-Drain for the form on the inside. Wait a month for the first set of blocks to cure and then go back and excavate the earth between each of those 4ft. sections and repeat the process until you've filled in all area between blocks. Connect your drain tile to the Form-a-Drain.

ONE TEAM - ONE FIGHT!!!

Mike

[John Kogel]

Have your contractor add a footer under the wall 4ft. at a time skipping every other 4ft. section. Make sure the contractor uses dobies and #4 rebar to reinforce the new footer and extends the rebar into the earth at either end of the footing excavations so that when the area between the first set of new footers is excavated there will be something to tie into. Use Form-a-Drain for the form on the inside. Wait a month for the first set of blocks to cure and then go back and excavate the earth between each of those 4ft. sections and repeat the process until you've filled in all area between blocks. Connect your drain tile to the Form-a-Drain.

ONE TEAM - ONE FIGHT!!!

Mike

To do that, would he be digging from the outside as well? In which case, he could lay conventional perimeter drainage around the outside, right? Then would there be any need for interior drains? Better to stop the water at the exterior, I would think.

[Tom Raymond]

Yes, but if he's already undermined the interior and at that point determined that there are no footers, excavating the exterior would risk toppling the entire foundation. If the basement is wet enough to have warranted an interior drain in the first place (and dependant upon soil conditions, water volume and pressure) he may have already significantly increased the risk of failure. Short of replacing the whole basement, Mike's got the right fix.

Last year there was a 1906 house near me that was excavated around for an addition. There was a moderate over night rain, and by the next morning one wall had fallen out from under the house. Slip formed concrete walls without footers.

[waynesoper]

I may be dilusional here but, If you have full clearance to add a temporary support inside of the exterior wall, could you not do the entire section at the same time?

I agree with the 4 foot rule as I have done that but only with slab on grade.

How do we know this is not a crawlspace or basement

[Rocon]

Have your contractor add a footer under the wall 4ft. at a time skipping every other 4ft. section. Make sure the contractor uses dobies and #4 rebar to reinforce the new footer and extends the rebar into the earth at either end of the footing excavations so that when the area between the first set of new footers is excavated there will be something to tie into. Use Form-a-Drain for the form on the inside. Wait a month for the first set of blocks to cure and then go back and excavate the earth between each of those 4ft. sections and repeat the process until you've filled in all area between blocks. Connect your drain tile to the Form-a-Drain.

ONE TEAM - ONE FIGHT!!!

Mike

The only thing I might add is to make sure that when you cast the new footing in under the foundation you should vibrate the concrete to eliminate any voids at the foundation to footing cold joint. You could easily have air pockets that will have waterproofing as well as structural repercussions.

Ramon

[Marc]

Have your contractor add a footer under the wall 4ft. at a time skipping every other 4ft. section. Make sure the contractor uses dobies and #4 rebar to reinforce the new footer and extends the rebar into the earth at either end of the footing excavations so that when the area between the first set of new footers is excavated there will be something to tie into. Use Form-a-Drain for the form on the inside. Wait a month for the first set of blocks to cure and then go back and excavate the earth between each of those 4ft. sections and repeat the process until you've filled in all area between blocks. Connect your drain tile to the Form-a-Drain.

ONE TEAM - ONE FIGHT!!!

Mike

What are dobies, Mike?

Marc

[Brandon Whitmore]

Marc,

It's blocks that hold the re- bar into place.

[hausdok]

I'd assumed it was a basement or crawlspace. To underpin a wall like that, you have to do a whole lot of excavation on the exterior but from the interior you might have to go down only a foot to 18 inches max. On the exterior you have to deal with landscaping and then backfilling in lifts and tamping every six inches or so; from the interior, you pretty much just need to backfill and tamp once.

ONE TEAM - ONE FIGHT!!!

Mike