Weatherization Nation 2: Digging to Higher Ground

August 7, 2019

How to dig your way out of a hole with gravity, foundation drainage, and common sense

Welcome to ProTradeCraft’s Weatherization Nation. A show about building smart from the start. Last week we got acquainted with this 75-year old brick home in Washington, DC that MARK IV Builders is adding to.

The old addition had some water problems, which began with the slope of the land, and was exacerbated by misguided roof flashing.

Ray: "...there were several things. If you looked at these outside corners, nothing but water damage and rot. The OSB plywood —you could just take it with your hands and peel it off like cardboard."

This week, we’re going to explore foundation drainage and digging our way out of a hole.

Sketch Desk: Planning for groundwater drainage

Building performance begins when rain hits the roof. Steep slopes move water down and away quickly.

Once the water is in the ground, the ground should take it away from the house. The back yard was sloping toward the foundation, so it was always wet inside.

The solution is to dig out the ground and slope it away from the house. MARK IV used a swale in the back to direct water away.

Another way to beat groundwater is through capillary breaks. Paint on waterproofing stops water from wicking into the foundation from the footings. 

Waterproofing is also painted on the foundation walls, and MARK IV goes the extra bit and uses a dimpled sheet on the outside. This allows groundwater to drain directly into footing drain. 

The drainpipe should drain to daylight and foundation water problems will be a thing of the past.

Next, detail the inside for durability and optimal IAQ: sealed and conditioned crawlspace. 


Git ‘er done: Keeping interior living space dust-free (and warm) during demolition

RAY: OK, so the homeowners are going to live through the first couple weeks of the construction process—

Hopefully, the homeowners will live MUCH longer than the first few weeks of construction. 

I think Ray means that they will live IN THE HOUSE during the first few weeks of the construction process. 

And then they will flee.

Ray: And so what we’ve done is we’ve taken the openings where the original house went into the addition and we put up temporary walls.  

We taped the edges to the drywall to any dust or air coming through the demolition process.

Ray says they use heavy-duty Gorilla tape because they are looking for longevity, not clean removal. They are not worried about damaging the drywall because they will be repairing and painting it later.  

RAY: But we don’t tape to the floors. That’s one thing we don’t do. 

Sticking tape on pretty much any floor is just begging for trouble down the line because of Murphy’s Law.

So we put some sill seal at the bottom and the top, pressure-fit your studs in there and you get a tight seal.


What’s Next: A Warm and dry crawlspace

Ray: So, we’re just through phase 1, we’ve got the original one-story addition down.

We’re going to come through here and break out some of the foundation, later on, next week.  

 

Last week: Introduction

 

—ProTradeCraft would like to Thank DuPont Tyvek for sponsoring this first season of Weatherization Nation and also for the technical assistance in getting the construction details and sequences correct.

 


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