Soil Grading Question

[spitfire557]

Hello all. This question pertains to an issue I have with grading around my house, not my garage - so hopefully that's okay. We purchased our house several years ago and I've been slowly chipping away at a number of issues we've uncovered. My current issue at hand is some grading near our master bedroom which is an addition. When they built this addition, they made it a step lower than the original structure (so our bedroom is essentially a 'sunken bedroom'). As a result, the foundation height is about 8" lower than the rest of the foundation. This area is also sloped downward, which may explain why they chose to go this route.

The problem is that because of the existing landscaping, the soil level is higher than the foundation. To make matters worse, we have wood siding which is obviously prone to rot. I've included some photos to hopefully help explain my situation. The blue painter's tape represents the approximate foundation height for the addition.

Does anybody know of a relatively easy solution to this problem, aside from re-grading the entire area? There is a retaining wall there that I would prefer not to dismantle. Thanks in advance.

 

[NWOhioChevyGuy]

Soil should be 8"+ below that sill plate to prevent any problems.

What is the lawn grade below that point?
That retaining wall / planter is doing you no favors for your problem. Is it just a planter? I don't see any need for a "retaining" wall there.

 

[BillK]

I dont see where you have much choice but to regrade the whole area. You certainly dont want the siding in the dirt. Doesnt look like a lot of slope. You will probably have to go almost to the road

 

[FredWanaker]

regrade and/or dig a trench and put in a drainage system that takes the water away to a lower point.

 

[spitfire557]

Soil should be 8"+ below that sill plate to prevent any problems.

What is the lawn grade below that point?
That retaining wall / planter is doing you no favors for your problem. Is it just a planter? I don't see any need for a "retaining" wall there.

We have about 15' of yard until it hits the road. The lowest point (road) is about 12" below the addition's foundation height. So not much slope at all. And yes, that is just a planter, not a legitimate retaining wall.

I'm thinking my best option is to dismantle a portion of the retaining wall and curve it into the house where the bedroom addition starts. And then regrade everything outside of the retaining wall from there. Not exactly the project I was hoping for, but oh well. I've attached a few additional pictures to show overall grading.

 

[FredWanaker]

there were probably some big trees that raised the soil in that area and that was added to keep water from flowing towards the house. I'd mark a spot 24' up on the siding from the preferred exposure, and then use it to find the closest path out to lower ground and make a swale towards it. You put the water level ends on a hose, fill it, one person holds the water level at your mark, and the other person walks around with a tape measure and the other end of the water level. Any distance to the ground more than 24" from the height of the water level is lower than the ideal depth. Figure out the best path and make your swale. Don't trust your eyes on what is level or not.

 

[FMB4]

I agree in that your retaining wall isn't helping the issue at all. It could, in fact, be the majority of your grade problems imo.

 

[PoorUB]

Looks do able to me, but yes, you need to get below any wood structure, the farther the better. Dismantle the planter/retaining wall and slope away from the house as best you can. I would want a good slope from the house, and it can level out a bit towards the street.

IMO, that whole planter/retaining wall is way too high, all the way to the other end of the house, not just at the step down in the foundation.

I can't believe what people do! Who would think it would be a good idea to put dirt against siding and wood structure?!

 

[csp]

We have about 15' of yard until it hits the road. The lowest point (road) is about 12" below the addition's foundation height. So not much slope at all.

You only need 1/4" of drop per foot of run to effectively drain away from the house.

 

[65ranchero]

If you want to keep the wall making sure the water will drain away from the house
drag all that soil away and regrade

 

[Leaflessshadetree]

Have you thought about digging the soil out of the planter? Depending on what type of plants you put in you may be able to leave it at the current height.
Another option could be to put in tile and make sure the bottom of the planter drains extra well.

 

[Bretny]

That dosnt even look like a retaining wall and if it is its very un needed. You have plenty of slope to play with to get proper grade away from the house so the wall isnt needed. Having soil upto the siding is a terrible idea.

 

[Bent Handle]

There’s nothing fancy about that wall, just take off the courses where it needs to step down. You can even reuse the top caps if you’d like. Remove the extra dirt and grade the interior of the planter away. Problem solved.

 

[CraigStu]

"I'm thinking my best option is to dismantle a portion of the retaining wall and curve it into the house where the bedroom addition starts. And then regrade everything outside of the retaining wall from there. Not exactly the project I was hoping for, but oh well. I've attached a few additional pictures to show overall grading."
I agree. You could grade down to below the road surface so you have a swale parallel to the road and bottoming out maybe 6 inches below the road surface and about 3 ft in from the macadam. Make this dimension = the width of your mower deck. One additional thought would be to replace the bottom most piece of wood siding w/ something plastic. The original Trex decking takes stain pretty well so you may be able to get a pretty close match to your existing siding. Or you might find a plastic siding that matches well enough so that one course of it looks OK. Or go w/ a neutral grey color so it looks kind of like a concrete foundation. There are so many new plastic products coming out all the time there must be something that would work to get your real wood further up from the soil.

 

[nadogail]

Can you put an interceptor drain in the planter to move ta accumulated water away from the house?

 

[spitfire557]

Appreciate everyone's response. My biggest concern with excavating the soil and leaving the wall up, is that even the bottom course of the wall is above the foundation height of the addition, so it would inevitably slope towards the house.

I am curious about using a drainage system and keeping the existing grading. I don't think there would be any way to do this without the soil being above the sill plate, which is certainly asking for trouble regardless of any drainage system?

 

[ericlar80]

You already know the answer - you need to have drainage. You should run a trench to a lower spot on your property, install a drain pipe in it, and then install a few drains near your house.

You could drop the dirt away from the sill in a 3' perimeter offset from your house, sloping down by 3/4" in total, and install the drains at the 3' distance. You want to have multiple drains in case 1 or more get clogged up with debris, and make sure you use a screen so the pipe doesn't clog. You will probably have a step-up to your grass where you could re-use your retaining wall blocks if you want.

If you don't fix it now you will be fixing the drainage and your siding in a year or so. Not to mention termites may get into your structure in the meantime...

 

[finn]

Remove the top few rows of the planter, so the top is below the bottom plate of the house wall.

Dig a trench next to your basement / crawl space and install a French drain, using washed gravel and fabric above and below the pipe and run it to daylight.

You can probably get by with keeping the remaining, albeit shorter wall.

 

[Chip03q9]

Appreciate everyone's response. My biggest concern with excavating the soil and leaving the wall up, is that even the bottom course of the wall is above the foundation height of the addition, so it would inevitably slope towards the house.

I am curious about using a drainage system and keeping the existing grading. I don't think there would be any way to do this without the soil being above the sill plate, which is certainly asking for trouble regardless of any drainage system?

Retaining wall needs to go then you will be able to slope away from house if not your going to have a big problem to deal with down the road .