Waterproofing Your Deck

November 1st, 2010

With all the rain we have had in the past month, Wilmington, NC home builder Mark Johnson Custom Homes would like to share with our readers our method of waterproofing a second story floating deck that has a finished ceiling beneath it. 

 After framing the upper deck subfloor with a slope, we install a rubber membrane on the subfloor that wraps up and over any doorways leading to the second story floating deck.

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The rubber membrane is then installed to completely cover the subfloor.

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Any penetrations coming through the deck floor (such as handrail posts) need to be wrapped with the membrane.

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Next, we install the floating deck system. This involves placing (but not fastening) treated 2×6 boards flat on the membrane. The reason it is called a floating deck is because it isn’t fastened to the framing beneath. We then cut treated 2×4 boards down to basically form a wedge. The purpose of this is to keep the finished decking where you stand flat and level. Remember that the subfloor decking still slopes under the membrane so the water that drips through the deck boards will still run down the membrane and away from the house.

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The picture below is the finished floating deck before paint and handrails are installed.

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This view (before paint and handrails) shows the finished ceiling beneath the second story floating deck.


Radiant Barrier Roof Sheathing

August 19th, 2010

We all know how hot attics can get in the summer months, causing HVAC systems to work overtime. Mark Johnson Custom Homes aims to educate both our clients and readers, so we’d like to share with you a Green product that we use in all of our homes called Radiant Barrier Roof Sheathing. 

Green Home Building in Wilmington, NCThe product name comes from the ability of the foil coating to be a barrier to the transfer of radiant heat. In the middle of summer, the temperature in attics using this product will be approximately 40% cooler than a home using traditional sheathing. The product is made by laminating a thin, durable sheet of aluminum to OSB.

We use LP® TechShield® in our homes because it is the only radiant barrier with VaporVents, incisions that penetrate the foil, glue and OSB substrate. This patented, post-lamination incising process allows LP TechShield panels to dry more quickly from construction moisture than other radiant barrier panels. Green Building in North CarolinaWithout this incising step, moisture could build up and lead to foil delamination.

But how it is Green exactly? Radiant Barrier Roof Sheathing helps reduce energy consumption. It’s ENERGY STAR®-certified and reduces the heat load on in-attic air handling systems, cutting monthly air conditioning bills up to 17%. Several other factors make Radiant Barrier an environmentally friendly building material; for more information on Radiant Barrier Roof Sheathing, click here

Mark Johnson and his team have extensive experience with Green building, including their Green home in Wilmington, NC. The home was not only Energy Star Certified, but also earned a LEED Platinum Rating, the highest attainable certification from the U.S. Green Building Council.

This article was featured in our August issue of The Precursive Planner, our free monthly e-newsletter. Subscribe to receive our home builder newsletter today!

In a previous blog post, we introduced our readers to our latest custom home in Wilmington, NC, which is being built just north of Wrightsville Beach and Figure Eight Island. The home, on Bald Eagle Lane, is currently at the framing stage of construction and the installing the air barriers is the next step for Mark Johnson and his team.

Wrightsville Beach, NC custom homeThe air barriers in this home, in the form of sheathing and drywall, control the home’s air leakage, keep moisture out of the home and help lower energy costs. Air barriers ensure that the insulation is working properly, since the insulation cannot work if air is blowing through it.

Bonus rooms in particular are infamous for being cooler or warmer than the rest of the home, usually because there was no air barrier installed on the short knee walls. But in this Wilmington, NC custom home, air barriers will be installed (see right), so that the insulation will be able to work to the best of its ability.

Mark Johnson and his team are currently wrapping up their second Energy Star home in the private Waterford Community in Leland, NC. (The first Energy Star home was in the gated community of Landfall in Wilmington, NC.) Part of the Energy Star certification process is the Blower Door Test to determine the airtightness of the home.

Energy Star Home in Leland, NCPictured to the right, the Blower Door is a powerful fan that is mounted to an exterior door and pulls the air out of the home. This ensures that the air pressure is low in the home and high outside and air will flow through the unsealed cracks and openings which will then be addressed.

Ensuring the home has the proper airtightness allows you to:

For more information on Blower Door Tests, check out this article from the U.S. Department of Energy!

Mark Johnson Custom Homes is also a premier home remodeler in the Wilmington, NC area! Check out our Flickr slideshow of our latest remodel in Figure Eight Harbor near Wrightsville Beach, NC!

Mark Johnson Custom Homes also has experience building in St. James Plantation, a private community in Southport, NC. These pictures are of a custom home we built for a client that especially appreciated our “dedication and attention to detail.”

Wilmington, NC remodelIn a previous blog post, introduced our readers to Google SketchUp and how we’re using it to help our remodeling clients visualize what their home will look like upon completion. We also aim to use our blog as an instrument to show you our complete building process from start to finish, and so we’d like to take to you the Prestwick division of the private community of Landfall, where we’re at the insulation phase of a current remodel.

At this home, located in Wilmington, NC, we opted for a Blown in Blanket (BIB’s) system with OPTIMA for its eco-friendly features, including a higher R-value. (R-value is a measure of insulation’s resistance of heat flow and the higher the number the better.) The BIBs system will have an R-23 rating in the 2×6 walls, which is extremely efficient compared to the standard batt insulation. OPTIMA is also cleaner going into the home and does not have to dry after installed, which so often delays the construction process.

To follow the complete building process for this and our other projects, subscribe to our RSS Feed today!

Custom Home on the Intracoastal WaterwayWe are excited to invite our readers to follow through the complete Mark Johnson Custom Homes building process via our blog posts! One of our latest custom homes is in Wilmington, NC, just north of the luxurious Wrightsville Beach and Figure Eight Island. This unique lot is located on the Intracoastal Waterway, complete with a private dock, gazebo and boatslip. We have just begun the preparation process for the sealed crawl space for the home, which is located on Bald Eagle Lane.

The first step with our sealed crawl space is to install the insulation and air barrier on the walls now, then run the 10 millimeter membrane on the floor. A dehumidifier will be added when the house is almost complete. There are many Custom Home on the Intracoastal Waterwayreasons we opted for a sealed crawl space, one of which is to combat high humidity which often results in mold in crawlspaces. While building on a raised slab foundation is more cost effective than building a sealed crawl space, some clients prefer the future remodeling flexibility that comes with a crawl space. Also, crawl spaces are easier on the knees.

Subscribe to our RSS Feed to watch our building process through this home and others!

Studio 2 Architectural Design in Wilmington, NCMark Johnson Custom Homes is excited to begin working with Tessa Romanowski, owner of Studio 3 Architectural Design, on an interior renovation and addition to a home in the Prestwick division of Landfall in Wilmington, NC. With previous experience in remodels, Mark Johnson and his team understand the anxieties that can sometimes accompany a remodel. And so they are eagar to begin utilizing the Google SketchUp 3-D modeling program with Studio 3, which allows the client to literally see their home’s potential for renovation and additions. The files created for each individual client are open to manipulation and can be shared with family and friends.

Tessa Romanowski had this to say about this homeowner in Landfall, in particular: “The client has an existing two-story space that contains her living and dining room. It is a soaring volume with lots of natural light and a wonderful spacious feel. Our client felt that she needed more sleeping space and wanted to maximize her square footage by adding a loft over her dining room. It was important to maintain the dramatic light quality and sightlines in the two story space, as well as to create a sculptural stair that was unobtrusive to the room.


The Mark Johnson Custom Homes team is excited to announce that we have broken ground on our second ICF (Insulated Concrete Form) home!  The home, located in Currie, NC will be completed in 3 months. The first home we built with ICF’s resulted in an amazingly eco-friendly home that is Energy Star Certified and was also North Carolina’s second LEED Platinum home (the highest attainable rating from the U.S. Green Building Council).
You may be wondering, “What are ICF’s?”
ICF Home in Currie, NCICFs are formwork for concrete that stays in place as permanent building insulation for energy-efficient, cast-in-place, reinforced concrete walls, floors, and roofs. The forms are interlocking modular units that are dry-stacked (without mortar) and filled with concrete. The forms lock together somewhat like Lego bricks and serve to create a form for the structural walls or floors of a building. Concrete is pumped into the cavity to form the structural element of the walls. Usually reinforcing steel (rebar) is added before concrete placement to give the concrete flexural strength, similar to bridges and high-rise buildings made of concrete. The forms are filled with concrete in 1-4 foot “lifts” to reduce the risk of blowouts like with other concrete formwork. After the concrete has cured, or firmed up, the forms are left in place permanently.
Why Build with ICF’s?
ICF Home in North CarolinaThere are many, many reasons for opting to build with ICF’s, especially in our area of Southeastern North Carolina, where we can sometimes have an active hurricane season. The structural integrity of the home has a stronger resistance to the forces of nature compared to framed walls and ICF’s create a structural concrete wall (either monolithic or post and beam) that is up to 10 times stronger than wood framed structures. There are minimal, if any, air leaks, which improves comfort and less heat loss compared to walls without an air barrier and reduce HVAC operating coasts from 30-70%. There is also a high sound absorption, which helps produce peace and quiet compared to framed walls. 

Mark Johnson Custom Homes uses LOGIX forms which are made of thicker foam. Thick LOGIX panels provide superior R-24 R-Value and additional strength so you can build straight walls quickly. LOGIX panels also accept standard electrical boxes.