Alford, Jackson County
Blower Door Testing in Alford, Florida
What happens when a new house in Alford is measured for air leakage, and when in the build it is ready for that.
Air leakage testing for new Alford houses
Big Bend Services, Inc. tests newly built houses in Alford, ZIP 32420, under the Florida Building Code, Energy Conservation. The limit in Climate Zone 2 is 7 air changes per hour at 50 pascals, and a house over it has its leaks corrected and is tested again.
To book, call (850) 819-6031 on a weekday from 7:00 AM to 4:00 PM, or use the form.
How the fan measures an Alford house
A blower door is a fan mounted in a panel that fits an exterior doorway. With the rest of the house left the way the code sets out, the fan holds the house at 50 pascals against the outdoors while the leakage is measured.
The airflow is set against the volume of air inside the house. The result is air changes per hour: how many times the air in the house would be replaced in an hour at that pressure, given as one number for the whole house.
Why the set-up matters
Leaving the house so the fan reads it right
The fan cannot tell a leak in the shell from a window left open, so the code fixes how the house is left, and each rule keeps something other than the shell out of the number.
Openings in daily use
Windows and outside doors are closed but not taped, and fireplace and stove doors are shut, so only the gaps around them count.
Dampers
Exhaust, intake and flue dampers are closed, as they sit when not in use.
One connected space
Interior doors stand open and every supply and return register is open, so the whole house sits at one pressure.
Nothing else moving air
The heating and cooling is off, leaving the test fan as the only source of airflow.
When to book
The right point in an Alford build to book
The code lets the test run any time after every penetration of the thermal envelope has been created. That means booking after the last trade that cuts through an outside wall, the ceiling below the attic, or the floor has finished.
Walls and ceiling closed
The drywall on the outside walls and on the ceiling below a vented attic is part of what holds the air in.
The last small openings
Exterior light boxes, doorbell wiring, the gas line and the cable or internet entry are all openings through the shell.
Windows and exterior doors hung
They are closed for the test, so they need to be in place.
Finishes are optional
Paint, floors, trim and cabinets can come before or after the test.
Room for a retest
Booking with some of the build still to go leaves time for sealing and a second test if the first number is high.
The number
What an Alford reading tells you
Just over 7
A small amount of leakage has to go, sometimes from one large opening such as a hatch that does not close.
Well over 7
More sealing is needed, spread across the places air leaves a new shell.
Leak paths
Where the fan pulls air through a new shell
While the house is held at 50 pascals, air moves through every gap in the envelope at once.
Around the attic access
The edge of a scuttle hatch or pull-down stair.
Top plates
Openings for wires and pipes through the tops of interior walls into the attic.
Plumbing through the ceiling
Vent stacks rising from the walls into a vented attic.
Boxes on outside walls
Switch and outlet boxes cut into an exterior wall.
Behind a tub or shower
An outside wall behind a tub, where the framing above can be open to the attic.
Window and door frames
The space between each frame and its rough opening.
Recessed cans and fan housings
Each recessed light and bath fan box in a ceiling with attic above, where it meets the drywall.
Where the wall meets the slab
The joint along the bottom plate of each outside wall.
Chases
A framed chase for a flue or plumbing stack left open to the attic at the top.
Dryer and hood ducts
The gap around each duct where it passes through an outside wall.
Booking
Putting the test on the calendar
Send the address, the permit number, the ready date and who to call on site. If the build runs behind, call the office and a new test date is set. A builder with more than one house can send them together, and each is tested on its own with its own result. Alford tests are booked through our office in Wewahitchka.
Who can book
Builders, superintendents and owners of a newly built house.
Other services
Gutters, a garage door and wire shelving for the same house can go on the same call.
Same county
Nearby towns for the same test
What to expect
Your test from call to result
- 1
Send the build details
Address, permit number and when the house will be ready.
- 2
Test booked
We give you a date for the test.
- 3
Test run
The house is tested once it is ready.
- 4
After a failed test
Corrections are made and the house is tested again.
Why 50 pascals?
Why is the result per hour when the test is shorter than that?
Is the attic hatch opened for the test?
Can the test run before the outside doors are weatherstripped?
Do the driveway and landscaping need to be done?
Get a quote
Request a Blower Door Test in Alford
Send the Alford address, the permit number and the date the house will be ready.
