# Regrading Foundation and Drainage Issues



## lindentree27 (Feb 4, 2014)

We wanted to regrade our foundation, but we've run into some stumbling blocks. Here are the original two problems we're trying to correct:

1) Water runs from the neighbor's yard underneath the deck
2) Water falls through the deck and pools underneath at the base of the foundation

IMAGES IN POST BELOW. 

Here are a couple photos that illustrate the problem:

Below: Water runs in the direction of the arrows underneath the deck


Below: Underneath the deck, the water settles in the area marked X.


We're not sure how to regrade underneath the deck, especially the area at the corner that gets runoff from the neighbor. 

In the photo below, you'll see that the grading is already VERY high around the corner. 


The previous owners altered the grading so that a sump pump would discharge, running the water parallel to the foundation (see image above). As a result, the slope doesn't run away from the house, but rather alongside the house. See the photo below for an illustration of the way the water runs. We no longer need to account for the sump pump discharge, as it now discharges on a different side of the house. 

*How do we deal with the water that filters through the deck, pooling along the foundation?*

We considered building a 16" retaining wall with railroad ties directly in front of the deck posts, as illustrated below. Then backfilling with topsoil and grading it away from the house. 


We don't really want to have to build a wall, but in order to maintain a 1" per foot change in slope over six feet, we need the dirt to be 12" high against the deck edge. You'll see below how high we'd need to build the wall at the base in order to maintain slope (white lines are what we'd follow for slope). If we build a retaining wall as illustrated above, do we continue it out beyond the edge of the deck? Water from the neighbor's yard does continue to flow here during heavy rains (blue arrows).


*As far as dealing with the pooling water, how do we address the slope running parallel to the foundation instead away from it?*

We're just so stumped! THANKS!


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## lindentree27 (Feb 4, 2014)

*Photos for above post*

We wanted to regrade our foundation, but we've run into some stumbling blocks. Here are the original two problems we're trying to correct:

1) Water runs from the neighbor's yard underneath the deck
2) Water falls through the deck and pools underneath at the base of the foundation

Here are a couple photos that illustrate the problem:

Below: Water runs in the direction of the arrows underneath the deck









Below: Underneath the deck, the water settles in the area marked X.









We're not sure how to regrade underneath the deck, especially the area at the corner that gets runoff from the neighbor. 

In the photo below, you'll see that the grading is already VERY high around the corner. 









The previous owners altered the grading so that a sump pump would discharge, running the water parallel to the foundation (see image above). As a result, the slope doesn't run away from the house, but rather alongside the house. See the photo below for an illustration of the way the water runs. We no longer need to account for the sump pump discharge, as it now discharges on a different side of the house. 

*How do we deal with the water that filters through the deck, pooling along the foundation?*

We considered building a 16" retaining wall with railroad ties directly in front of the deck posts, as illustrated below. Then backfilling with topsoil and grading it away from the house. 









We don't really want to have to build a wall, but in order to maintain a 1" per foot change in slope over six feet, we need the dirt to be 12" high against the deck edge. You'll see below how high we'd need to build the wall at the base in order to maintain slope (white lines are what we'd follow for slope). If we build a retaining wall as illustrated above, do we continue it out beyond the edge of the deck? Water from the neighbor's yard does continue to flow here during heavy rains (blue arrows).









*As far as dealing with the pooling water, how do we address the slope running parallel to the foundation instead away from it?*

We're just so stumped! THANKS!


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## Daniel Holzman (Mar 10, 2009)

It is very difficult to tell from photos the relative elevation of one point versus another. When planning grading, the best way to start is by creating an accurate topographic map of your lot. This is usually done using a builders level and a level rod, which can be rented for little money from a rentall type store. You can also use a rotating level, which can be purchased for less than $100. Course you have to know how to use the tools, but they generally come with instructions.

The idea is to create a topographic map of your lot, with points every ten feet or so horizontally, typically accurate to about 0.1 feet (about 1 inch) vertical. Once you have the plan, you can figure out which way you can drain the water, where the low spots are, and you can develop a grading plan, maybe include a swale or a ditch. Without an accurate topographic plan of your lot, it is difficult or impossible to design drainage. If this seems too difficult, you can always hire a surveyor or an engineer to do the work, but this can be expensive.


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