How best to close off the open bottom of a new shed?

June 13, 2018 2:44 PM

We have a new shed -- yay! It's on uneven ground, though, so the builders put it up on cement blocks to level it. All well and good, but we're concerned that small animals will see this as a superb place to make a den. We'd prefer that they didn't. What's the best way to block off that space?

Of course, some critters will certainly be able to get in; insects, spiders, what-have-you. But neither the chipmunks nor the squirrels will be interested. There don't seem to be any stray dogs around -- maybe a stray cat or two. We have snakes, so they may like it under there. Currently there is nothing under the shed but some moss. Will those lattice panels that ones sees in the hardware store form an effective barrier against critter incursion? I can't think of anything else that might do the job for us. The shed is about 5 inches off the ground on one end, and 27 inches on the other.

posted by Guy_Inamonkeysuit to Home & Garden (10 answers total)

Those lattice panels are probably your cheapest option. They'll block raccoons and such, but not so much rats or mice. You'll drive yourself insane trying to build rat-impervious barriers, though, so I say you just stop there and then deal with a hypothetical rat infestation by the usual methods if it ever becomes non-hypothetical.
posted by tobascodagama at 2:50 PM on June 13, 2018 [2 favorites]

My biggest concern would be skunks, honestly. They do den under buildings when it gets cold. If you put up lattice make sure it's sturdy enough to withstand a creature of that size and well-anchored.

If you have a dog, that would help deter critters from moving in. You might also put some of those critter-repelling powders (that smell like coyote urine or whatever to other animals) down there on a regular basis.
posted by emjaybee at 2:59 PM on June 13, 2018 [2 favorites]

I wouldn't recommend the wooden lattice if you're really worried about small vermin -- try garden cloth, which is actually heavy metal screening. I used it under my shed and it keeps the skunks out.
posted by suelac at 3:11 PM on June 13, 2018 [9 favorites]

The first year I lived in my house a groundhog lived under my shed. When I brought out folks from the local wildlife center that helps to humanely discourage such things, their recommendation was to dig a 1’x1’ trench around the shed and secure L-shaped metal mesh underground and then backfill. Apparently that’s the best way to prevent diggers. So I’m not sure if lattice from shed to ground will be especially effective. Then again, you have so much space underneath your shed, I wonder whether it would even be attractive to many critters— it sounds very exposed. The lattice might have the opposite effect of making an otherwise fairly open space more “cozy”!

FWIW, when I found out the cost for the underground barrier for my fairly modest-sized shed, I decided to live with the critters. In nearly 10 years, I’ve only had groundhogs and rabbits take up residence. Aside from bunnies nibbling my cucumber seedlings, they haven’t been a nuisance. While I regularly see skunks pass through my yard, they don’t seem interested in moving in.

Good luck!
posted by kittydelsol at 3:42 PM on June 13, 2018 [4 favorites]

I'm going to recommend the one-two combo of lattice and hardware cloth, with the latter stapled or glued to the former. It makes it a little easier to secure/hold down, especially on that side where you have a 27-inch gap.
posted by Lyn Never at 4:07 PM on June 13, 2018 [2 favorites]

I have such a shed, pretty much the same configuration as yours. When I bought the property, the previous owner who built the shed had filled in the gap underneath with stacked slate stones. This had pretty much the same permeability for small critters as lattice would have. I decided to use the stone elsewhere as a garden retaining wall, so the shed has had its underside nakedly exposed for years. I think the occupants have included foxes, skunks, groundhogs, and smaller fry, but they have not bothered me, nor I them, and they're welcome to it. So I second kittydelsol. Just be happy to be providing some habitat for your neighborhood wildlife.
posted by beagle at 4:08 PM on June 13, 2018 [5 favorites]

It is actually pretty hard to keep animals out of a space like that, because they'll chew anything softer than metal and tunnel under anything else. If you want an effective barrier, kittydelsol's method would probably be the best. The metal mesh will rust out in a few years though if it's in contact with the earth, and then you'll need to redo it. Other alternatives include the aforementioned stacked slate, or poured concrete.

I would encourage you to just not worry about it. I mean, what's the worst thing that could happen?
posted by Anticipation Of A New Lover's Arrival, The at 4:14 PM on June 13, 2018 [1 favorite]

We built a floating deck a few years ago and I researched the heck out of this because there are a lot of skunks around these parts. We did the trench-and-screen method described in this SFGate article (they are always a good go-to for home projects). We used something like this Home Depot product and cut it in half height-wise - I don't recall the gauge but it ain't chicken wire. It was tedious as heck and hard on my hands, esp. getting around the corners, but so worth it; it is very effective. The key is to bend it outward underground, so they can't burrow under and nose it inward. They dig down but not backwards, so they can't get underneath.
posted by headnsouth at 4:28 PM on June 13, 2018

Digging a 1'x1' trench and lining it with hardware cloth is a lot of work, but will be fairly effective on the several year horizon.

On the flip side, you may be better off in terms of ground hogs, possum, skunks, etc. to keep the space open and airy, rather than trying to seal it off. Most critters won't like the space unless it is fairly sealed and cozy.

The worst case is a casual cosmetic seal that doesn't keep much out, and could e.g. hide whistlepigs until they have huge litters of babies and undermine your shed.
posted by SaltySalticid at 4:31 PM on June 13, 2018 [2 favorites]

Response by poster: I was thinking of just leaving it open, as SaltySalticid suggests. We live in NC, and there don't seem to be any groundhogs around. (We lived in PA until last year, on a farm and there were plenty of groundhogs up there.) We've had a rabbit or two; no skunks that we've seen, though I'm sure some are around -- and no possums, probably ditto.
posted by Guy_Inamonkeysuit at 4:57 PM on June 13, 2018