Sealing Windows and Doors

1. What is the basic process to seal a window or a door? Is it different for a window vs. a door? All windows and doors (regardless of construction) have a rough opening ½” larger than the actual unit. Once the window/door is installed, leveled and plumbed with shims, the air space around the rough opening is spray foamed with “open cell” insulation. This is so the “closed cell” alternative doesn’t expand and pinch the window/door.

   
   

2. Are there different ways to seal them?  After the W/D is installed, usually a 2” wide and strong ZIP type tape is secured over the exposed aluminum/vinyl exterior window/door flanges.  Then, you are ready for flashing and exterior trim.
   

3. How is sealing a window or door in a LOG home different than a timber frame or stick home?  A structural LOG home typically requires window/door trim details to allow for shrinkage and settling.  Sometimes up to 1.5” above a 7’-0” door is needed.  Flashing above the W/D to allow for settling is another detail.  Slotted jambs on the sides (with nails/washers and not driven too tight) allows the logs to settle.  Open cell foam at the top will compress without pinching the W/D.  Most manufacturers detail these openings based on their specific system(s).  Kiln dried logs shrink LESS, but they STILL settle from the weight of 2^nd floor and roof.  Glulam logs not as much.  Large hand-crafted “green” moisture content logs settle the most.  Log sided, timber frame, SIPS and conventionally framed  systems are built “tight” without settling.
   

4. What does the contractor do vs. what the Perma-chink products do?  Perma-Chink’s role is to seal the finished W/D trim and siding/roof timbers to the interior and exterior walls (as well as corners, subfloor, gable end siding, roof framing to perimeter walls, etc.).  It keeps the air and insects from infiltrating and looks great even when the W/D is properly installed. 
   

5. What Perma-Chink products put the finish touches on sealing a door or window? Is it for aesthetics or functionality? Both?  PCS Energy Seal is a textured caulking that accepts stain for a seamless transition.  The Perma-Chink product is a flexible textured “mortar” that seals wider gaps or chink spaces and provides an attractive “contrast” to the logs….as it was done historically. 
   

6. Do you have any advice for a log homeowner regarding the sealing of windows or doors? What's the best way to ensure against future leakage?  A blower door test and infra-red camera is the best “insurance policy” for any homeowner and their licensed General Contractor to work towards and discuss before the contract is signed.  In most climate zones, building code requires 3 ACH at 50 pascals.  This is deemed a “tight” home by new standards, and an air-to-air exchange system is often built into the HVAC design.  Dated ACH 50 test results get signed off by the licensed professional and affixed to the electrical panel for future owners…..if enforced by the local building department. 

For Existing Log Homes:  After a structural log home has finished shrinking and settling (2 years?), an infrared camera can detect the air leakage locations for spray foam and/or Energy Seal caulking management.  I have a SEEK Thermal camera adaptor for my iPhone that works OKAY when temperature variables exceed 30 degrees between the interior and exterior.  More expensive FLIR type cameras are certainly better. 

Word of Caution:  Building a “tight” new home is always suggested.  But so is professional HVAC design to eliminate interior moisture caused from long showers, gas powered appliances and pool areas that don’t have exhaust systems automated when humidity exceeds 45%.  Vapor drive is another discussion that causes problems when it’s 70 degrees inside and 20 degrees outside without adequate ventilation.