Pole Shed Moisture Problem

[jsduke]

Hello all.

I had a smallish (20X24) pole shed/garage built for my tractor, atv .... this past summer. The building was erected before I took delivery of the tractor (an insurance prerequisite) and the building was completed without too much concern for site levelness and drainage as those areas could be hit with the tractor, after the fact.

Well it's after the fact now. The levelness of the building site has been mostly addressed by the placement of 30 - 40 tons of crusher run (aggs. + dirty fines) product with a cleaner product for top coating still to be added. The problem is the building is still lower than the higher ground nearby and water from the rains we've been getting sneaks (subsurface?) into the building and keeps rewetting the fill inside driving the humidity up over 90% and it's very slow to dry out. /forums/images/graemlins/mad.gif

To complicate things I've got underground utilities running approx. 30 inches in front of the overhead door.

The good news is that except for the front (especially the right front) and about a third of the right side, the building is higher than the surrounding area.

I've got a couple of ideas:

1). Hand dig (no bh on tractor and maybe too close to utilities) an L shaped trench across front and down right side of building, lay 6 in. of aggregate, place 6 inch perforated pipe on agg., more aggregate then fill to ground level.

AND/OR

2). Place water blocking textile between current fill and clean top coating product.

Since I've not done any of this type of work before, I'd really appreciate feedback or any other ideas.

Thanks.

duke.

 

[DavidJ]

<font color="blue"> 1). Hand dig an L shaped trench across front and down right side of building, lay 6 in. of aggregate, place 6 inch perforated pipe on agg., more aggregate then fill to ground level. </font>

This sounds like your best bet. You could use 4" pref pipe instead of 6". Also work it to where the trench tapers off at the lowest point or close thereto.

<font color="blue"> 2). Place water blocking textile between current fill and clean top coating product. </font>

If you did this you would still have water entering the building and driving the tractor over it will tend to break up the substrate causing major problems later on.

 

[F350driver]

I agree. Placing a substrate under the gravel will likely lead to just having a problem later with a bunch of plastic migrating to the surface.

You may want to also try a swale. A swale is kind of like the oposite of a ditch. With just a little backblade work (depending on the ground...rocks and such) you may be able to do a small cut and fill so that you make a ridge to block the water and divert it around the structure.

That coupled with the hand ditch around the drip line of the structure should do the trick. I'd fill the ditch with loose gravel over the top of the tubing and up even with the surface. Make sure the ditch has an outflow downhill from the buiding. At the outflow area you might even want to put a dry well (old barrel filled with rock and buried as a down hill place for all the water to run into.

had a similar problem with my house these techniques work pretty well. Keep us posted!

Jim

 

[jsduke]

Thanks.

I kinda thought the plastic barrier had some downside. A swale would be easiest but I'd have to run across it with the tractor to get into the building.

Would a 4 inch pipe be enough? It would be easier to handle as well as require less hand digging. What about crushing and the depth of the pipe?

Another idea I had was to dig a shallow (12-18 inch) trench tilted for runout and fill it with agg. or maybe line the bottom and the side closest to the building with water barrier and then fill it with agg.

I like the dry well idea F350D. I'm just curious as to the exact function of the barrel. Could I just dig a decent size hole at the pipe outlet and fill it with agg?

duke.

 

[grandad]

I have been building a similar pole shed at the bottom of a small ravine for temporary equipment storage... attached is a photo - I hope - of the poles and trusses going up early last spring. Maybe you can see it's just at the foot of the grade, so we knew there was going to be a water problem.

We dug a small trench on the uphill sides (to the right and facing the camera in the picture) and added 4" perf in an "L" going around the sides to opening to daylight at the left. Worked great... my only other recommendation is to use a fabric silt blocking sleeve around the pipe to prevent clogging.

 

[Rch]

Catch basin
Adding a catch basin to perforated plastic tile on the hill-side of a building and a little contouring to channel the water away works nicely. Fleet Farm sells a plastic version that you can drive over for 20 bucks.You can cut into the sides to route the pipe. It's one of the uses of recycled milk bottles. This link has steel ones on the first page but scroll to the 2d page and I see a $38 ,14" that must be plastic. There is an outfit in Appleton WI that makes these with 'Drainage" in the name. The local building/plumbing supply has another version. You can place it any where along the course of the perforated plastic pipe. Wrap the pipe with landscape fabric if you didn't buy the type with the polyester sleeve already on it.

I've also used them for housing the shut-off valve in an underground watering system for the garden and lawn.

 

[5030]

I haven't heard the term "swale" used in a long time. Around here we call it a "french drain".

I did one in front of my pole building as the grade slopes into the building itself. Because I wash equipment in front of the building I dug down with a hoe about 4 feet, lined the bottom of the trench with 6 mil and backfilled with No.5. I tapered the drain toward the lowest point at the far side of the building.

I put it in over 10 years ago and it works well. Just like a floor drain with no floor!!

 

[F350driver]

Looks like you've got a lot of great ideas to try out.

As for driving over the swale you could put a culvert on the uphill side of the swale and some more on the downhill side if necessary. That would give you access.

Just to clarify on the swale concept. What I am talking about is the creation of berm above your barn that is big enogh to change the direction of water flowing downhill.

The purpose of the old barrel, plastic metal or whatever, is to prevent the ground from collapsing into and filling inbetween the cracks in the rubble.

I forgot to say to punch a lot of holes in the old barrel and cover the dry well up with an old piece of plastic or tarpaper to prevent soil infiltration from above. Take an axe or chisel or any other appropriate tool and punch the holes in the barrel so that water can seep into the surrounding soil. The idea is to bury the whole thing out of sight.

Good luck with your project!

Jim