Keeping Soil Off Base of Porch

[zeruel]

I've got a back porch, and a short of shed like structure under my back porch  that forms the wall for the stair well to my basement (https://imgur.com/a/KMuJz1B).  That brown wooden structure goes maybe another foot or two into the ground.

It was this way when I bought the place, but I think I should try to keep the dirt off it for the preservation of the wood and to keep pests away. But what is the right way to do this? How can I keep moisture way from there?  I also want to keep it off the pieces of the porch itself pictured.

       

[Frankies Girl]

Any wood normally used for that type of construction is going to be treated (pressure treated and likely chemically treated as well) to resist rot/insects. BUT wood is still eventually going to rot/attract bugs (termites/carpenter ants) once it starts getting consistently damp/rotting. The two things I've learned recently:

If at all possible make sure there is no soil/dirt actually in contact with the wood. Should be properly supported by stone/piers/concrete/whatever to prevent direct ground contact.

And

Air circulation is going to significantly help ward off the rot/insect invasion.


Your pics show lots of soil in contact with wood. It may be as simple as get a small shovel and pull it back so there's some inch or more space between the surface (more is always better) BUT you also have to consider drainage and the grading so you don't accidentally dig a small pond under your steps so the water from rain and gutters all pools under there and creates a humid petrie dish and make it much, much worse. Proceed carefully and go slowly and check the slope - away from the house/under areas is good!

You do seem to have decent air circulation in that the area is not boxed in so tightly that it can't breathe and dry out if it does get damp under there, and there does not appear to be any mold/algae/dampness indications. That is good, but having wood literally buried in the ground is like offering an invitation for termites to come have a bite... so I'd inspect the wood stuff carefully and see if it is removeable without damaging anything structurally. Do you really like that storage area? Because if it was me, I'd be removing/regrading the soil as much as I can, but also removing any of the non-essential wood and retrofitting if possible with cement footers (doing this in the next month actually with 3 porch posts that were just stuck into a hole and then filled in with cement so the wood itself is covered with a few inches of dirt - of course they rottted at the bottoms!)

If you don't move the soil or somehow reseat the wood in contact with the ground, it WILL eventually start rotting if it hasn't already, so you may want to review soil treatments to knock down the wandering subterranean termite colony from setting up shop. If the wood does not have a finish you could look into using some BoraCare to kill/deter termites, but do the reading on it; it can be pressure treated, but if wood is painted or otherwise coated so the actual surface of the wood isn't open, then you won't have good penetration of the BoraCare, and likely won't last very long protection wise. BUT it is a great, safe and easy to use product that should provide decent protection for that structure if you can use it.

I am not an expert, but I just removed a rotting wood deck built around 20 years ago (built before I bought the house) that had been improperly seated in direct contact with the ground. SO LOTS OF READING/RESEARCH in the last month...

Despite the wood deck being pressure treated boards, it still rotted, and had a nice termite colony move in. I found 4 mud tunnels in a 3 foot range. Once we removed that section, we chose to do a complete house trenching/perimeter treatment with some pro termiticide called Taurus SC(it's generic Termidor SC - both have the active ingredient Fipronil same thing as in some types of pet flea protection). It is however very toxic to most insects and can be harmful to other wildlife and may not even be sold to homeowners in your area (it is in mine because it is the only thing that kills raspberry crazy ants and the best long term termiticide). So had to be really careful, and took extra cautions about runoff/removed and protected any plantlife that might attract bees since they are one of the susceptible beneficial creatures that can be killed if they come into contact (is also harmful if it does get into the water table/runoff into aquatic areas as it will kill fish/other fauna). BUT used according to directions it is safe for pets/people and once the treated soil is dry pretty much safe to everything else except for anything that burrows into it.

It is a non-detectable, slow kill termite/ant/roach/general insecticide that will bond with the soil and stay there for 10 years if done properly. So termite passes through the area, it picks it up, takes it back home, and anything it touches in the colony (other bugs/walls etc) also get contaminated and when ingested during feeding/grooming, will poison them over a longer time period. This means the whole colony including the queen will eventually be destroyed and they'll not know to avoid the areas since it's not detectable like other regular insecticides.

[zeruel]

So, there is a concrete footer down there, at the base of the wood, it is just buried under a foot or two of dirt.

This area is some what protected  from water by two stories of porch above it, and the second story has a rubber roof on it; rain water doesn't really accumulate there to any significant degree, although there is a little bit that might splash in there. That is probably the main reason it hasn't already rotted :)

I can definitely dig a small trench to give it in air gap from the dirt, but what can I put in that gap that will actually keep the dirt from collapsing back in?

I can regrade it some what, and remove some dirt, but unfortunately taking lot of it away would either involve me digging a pit (and trying to keep water out of that some how), or regrading my neighbor's yard.

[Frankies Girl]

So, there is a concrete footer down there, at the base of the wood, it is just buried under a foot or two of dirt.

This area is some what protected  from water by two stories of porch above it, and the second story has a rubber roof on it; rain water doesn't really accumulate there to any significant degree, although there is a little bit that might splash in there. That is probably the main reason it hasn't already rotted :)

I can definitely dig a small trench to give it in air gap from the dirt, but what can I put in that gap that will actually keep the dirt from collapsing back in?

I can regrade it some what, and remove some dirt, but unfortunately taking lot of it away would either involve me digging a pit (and trying to keep water out of that some how), or regrading my neighbor's yard.

I am not an expert and I do hope some of them that have helped me out recently will come help you too because they likely know of many options here that I haven't a clue about.

There are no permanent solutions, as dirt will eventually accumulate again. I'll bet when that area was built those concrete footers you found were slightly above ground. It's amazing how nature is just a constant attempt to return things back to the earth/rot/break down things.

If it was me, with the area not being saturated and looking pretty decent drainage wise, I would likely try to just remove enough soil to not have contact and then check it once or twice a year for any signs of insect activity and also to sweep the dirt back out/regrade as needed. And I'd also take a hard look at removing anything wood that isn't structurally needed/wanted. Just basically an overall tidying and then monitor/maintain.

Next level (and likely overkill for you) would be to do a full on regrade and lay cement pavers/pour concrete/dig out the footers and replace with properly seated (this is what I'll be doing soon), along with adding a French drain type stuff to help move water away from areas you don't want it to go (if that is even a problem).

But again, I'm no builder or DIY guru so don't take anything I say as best case/definitely do this way. ;)

[Paper Chaser]

I'd probably remove or redistribute the soil so that it's a few inches inches below the wood. Then just rake it out as flat as you can (with slight slope away from the house and the wood), unroll that landscape fabric on top of the soil and top it with about an inch of pea gravel so that the gravel would sit at or below the bottom of the wood. I'd probably go ahead and do the same thing on the outside of the walls too so that you'd have a 1-2ft band of gravel on the outside of the walls (or more if nothing will grow there due to lack of sunlight, etc). The gravel will hold less moisture than dirt and having the dirt trapped under fabric and a layer of rock will keep it from moving around or splashing back up onto the wood when it rains.

[lthenderson]

From the sounds of things, regrading so that the soil to below the level of the wood and so that it won't eventually settle back up next to the wood isn't really an option. There are a couple temporary solutions mentioned above but if this were my house, I would pour concrete piers or a wall onto of the footers you said are below the wood so that the intersection of concrete and wood is going to be above grade and moisture. One of the advantages is that termites don't like the sun so they build mud tunnels to get from soil to wood. If you are just pulling the soil back an inch or two, they can easily build a tunnel and get back to work. With concrete, they generally won't build tunnels across it unless it is six inches or less.