# Leaving Excavation Open over Winter



## quantumflux (Jan 4, 2015)

All,

I'm located in western Massachusetts, building a spec house w/ walkout basement on a sloped wooded lot. Footings will be pinned to ledge (shallow ledge) everywhere to prevent differential settling. I've typically only done interior work (gut renovations) and smaller exterior jobs before, so I'm subbing out most of the exterior work. 

I'm considering having the land cleared, graded, stone put down for temp. driveway and the excavation done this fall, but, there is a risk I won't get the foundation in until spring due to scheduling.

I'm thinking erosion control, and fencing around the basement area, and making sure that there aren't any areas that animals/people can't easily get out of in case they get past the fence.. Just wondering if this is viewed as a non-issue and/or things to watch out for/plan for.

Thanks!


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## quantumflux (Jan 4, 2015)

Hit post too soon..

I'm also planning to (potentially) have to pump out water that collected although the soil is pretty good there. Sides caving in and having to be cleaned up are expected as well (to some extent.)


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## Seven-Delta-FortyOne (Mar 5, 2011)

Potential issues:

If you have clay soil, it can take awhile to dry out. With no topsoil, it's gonna be a muddy, slicker-than-snot mess. 

Sides can cave, then you have some clean-up to do, not to mention possible danger.

Straw wattles are absolutely necessary. Required in my area, along with sheet plastic over the spoils.

Getting the base compacted might be tough after the rain softens the excavation, so you might end up having to dig even deeper, and bringing in engineered fill.


Delta


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## dayexco (Mar 4, 2006)

Have no idea of frost situations there, here all your walls would heave


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## tgeb (Feb 9, 2006)

Do the grading, sediment control work, install the driveway this Autumn, dig the foundation hole when you are ready....What will it take, a day with a track loader, unless it's a big ass house, then 2 days? 

Otherwise, you'll have a mess on your hands when things thaw out in March/April.


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## Fouthgeneration (Jan 7, 2014)

Here, you aren't supposed to pour footings on clay that has been allowed to sit under water after being exposed.... you are forced to overdig and restore with rock or more concrete depth........

Thus final trim the same day as pour...

Rough grade the site, cover the footings with straw/hay or concrete blankets, burn off the hay, dig and cover the footings during the winter when the best help is looking for work....

If needed a dewatering sump pit/well points will speed the plow/job.

The trick is to get the temp driveway located & Graded where the final driveway can use it as a base. Proper prior planning prevents piss poor performance, FFA 1978


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## mtnxtreme (Sep 10, 2017)

We live in the Catskill Mountains, we go down 4 feet, footings and drains, walls to height with a floor system on the foundation, then we install EPDM roofing membrane loose layed over the deck, backfill with gravel, never had an issue, anything less you will be setting yourself up for heaving and walls pushing in. We get some nasty winters up here, never had an issue, even with block ( with dura-wall every other course and rods filled solid every other web) we are 3rd generation mason contractors, good luck !


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## Fouthgeneration (Jan 7, 2014)

if the lot is large enough and has enough grade change, one could install an interceptor 'Ag' tile on the uphill side of the building site a year earlier to 'dewater' the foundation area running the tile to day light or a local creek or storm sewer. With intakes at any obvious low spots.

Swamp lovers could plug the tile when the house and drive are completed......:laughing::laughing:


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## Davisentnw (Jun 19, 2017)

You would be best served to do things right and wait til spring to do the excavation. I think you should do what you can up to excavation and then stop or go if you are certain you can pour to foundation in time. If you land clear and excavate and leave you are going to get sloughing and cave ins most likely. 

Joe
Davis Enterprises


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## rino1494 (Jan 31, 2006)

Wait till spring and dig. I have been in those situations and the bottom of the excavation is a sloppy mess and you will be forced to over excavate and replace with structural fill and compact. Since this is a spec house, any additional costs are lost profits.

Clear the lot, install driveway and erosion control. If possible, get the septic system in if it is an on-site system.


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## Fouthgeneration (Jan 7, 2014)

If you install the septic tank, if it is plastic or other light weight material, fill it full of water so it doesn't float up in the spring thaw.....

Keep the cranes, concrete pumps, and 12 ton forklifts OFF the tank and fields.....


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## rino1494 (Jan 31, 2006)

Fouthgeneration said:


> If you install the septic tank, if it is plastic or other light weight material, fill it full of water so it doesn't float up in the spring thaw.....
> 
> Keep the cranes, concrete pumps, and 12 ton forklifts OFF the tank and fields.....


True story, we installed a 1,500 gal. concrete tank that weighed 8,000 lbs. We backfilled all around the tank leaving the lid exposed so we could work and install our piping. Thunderstorm came and it downpoured and it caused our tank to lift. I had to dig all around the tank and the tank manufacturer came back, lifted it out of the hole, I clean out the hole and he set it back down. 

Same thing with underground propane tanks. We always get them filled right after installation.


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