Making Andersen Window Extension Jambs

[backhertz]

Greetings fellow wood chippers. I had all my windows replaced with new Andersen windows- 400-series, I believe during a renovation/enlargement of our house. Had my crystal ball been working I would of done little as housing values really nosedived. Fortunately my contractor did not order extension jambs as I understand rarely do they fit, plus my sheet rock sub used 5/8" sheetrock on the walls. I also had 1" thick R-7.2 4'x8' sheets of rigid foam as additional insulation on my 2"x4" stud walls. I converted the house from an oil-fired forced hot air heating system 80,000 BTU /hr with a typical A/C A-coil to a closed-loop geothermal heat pump which uses two 600 foot loops contained in two 300 foot vertical well/bore holes.

The old 50-year old heating system was never sealed or insulated plus was full of 50 years of heavens knows what because the only return was right behind our front door where whatever was brought into the house was sucked right into the single return duct. My heat pump blows 46 degree air in the summer which is the main reason for insulated supply trunk & flexible duct lines otherwise the high humidity which used to leak in would cause wet spots.

I also had the house air sealed with closed-cell foam sprayed on the underside of the roof sheathing and between the studs and also added a 14' x23' master bedroom (where the garage roof used to be) while downsizing my Manual J calculated heating needs from 80,000 BTU/hr to 48,000 BTU. Our attic has no ventilation, but I installed a separate ERV- energy recovery ventilator which supplies fresh air changes & also acts as bathroom exhaust ventilators by using American Aldes ZRT registers- going from a constant 20 CFM to 200 CFM when someone activates a timer which causes a baffle door in the ZRT to open up & kicks the ERV into high speed which effectively removes the excess moisture in the bathrooms while delivering fresh air into the bedrooms.

Being semi disabled, this has been a several year process which also includes a solar power system that has generated more electricity than we consume each year. NJ offered some high incentives to motivate people to switch to green energy plus there is a 30% federal tax rebate on the entire cost of the solar & geothermal systems.

Our attic instead of being 130 degrees in the summer is maybe 78 degrees as we keep the temp at 72 degrees. Closed-cell foam is remarkable stuff when applied properly. My garage /wood shop has not required A/C or heat as in the summer, the foam keeps the interior (which is completely separate from the house) not hotter than 76 on a hot summer day or 42 when it is 20 degrees outside. Once I get the windows & all done on our upstairs, I'll be able to move into my man-cave and never come out- except for meals...<smile>

Here is a link that shows pretty much the profile of the extension jamb sides, head and sill: http://www.andersenwindows.com/servlet/ ... inary=true

What I am looking for are ways to make my own extension jambs. I noticed on the window there is a dado cut in the window to receive what I believe is called a shallow tenon ( I'm not sure if that is the correct word) that fits in the shallow dado of the window.

So I'm looking for suggestions & would thank in advance anyone who could assist in making it a simple process. My Power Pro headstock is down right for repair. But for some reason I believe there must be probably a half dozen ways to accomplish the profile as simple as a couple of rabbets simply cut the the same depth so the jamb assy fits tightly & centered on the window frame. For all I know there might be a router cutter made to cut that profile that will also cut what appears to be bevels on what I call the tenon on the front of the extension jamb.

Since the windows were already installed, I only see the trim screw option as my best way to attach the extension jamb to the window and no need to put cut an angle on the extension jamb for attaching the jamb using the one inch fastener option.

I bought a True Trac after watching this EZ Track video on extension jambs & figured, I could accomplish the same thing like is done in this EZ Track video: http://www.youtube.com/watch?v=qTYu5nIcoxs

It seems simple enough. However, this method doesn't take into consideration the front profile detail on the Andersen extension jamb. I have 6 windows of one size; 3 of another; 3 of another; one double window constructed out of two. I need to make extensions for two doors- my back door & a patio door. The doors are flat, so they will not be a problem- I believe. I plan to make sort of an assembly line.

In retrospect, I think the windows and doors should of been installed first and then the rigid foam insulation panels. But it's 6 of one; half a dozen of another. Please bear with me as I worked as an engineer and it seems I can take the easiest task and complicate it to the nth degree. I'm in recovery...

Yours in safe woodworking,

Tony

[anmius]

I was unable to get your Andersen Window link to work for me (on Firefox and IE) so I am unable to picture the issue with the extension jambs. I have installed a number of "400" windows and have never had any kind of issue with the standard extension jambs from Andersen. They are available in thickness (width) from 4-1/2" to 7-9/16." And they can be trimmed in the field to match an unusual thickness. Now, if you installed replacement windows, that could be a different issue since the extension jambs are only available in 5-1/4", 6-9/16", and 7-1/8" thickness.

With a link that I can get to work for me, I might be able to help you a little more.

[JPG]

He does not have the Anderson extensions and is trying to come up with a way to make them.

I would expect the shallow mortises and tenons to have tapered sides that ensure proper location. The outside profile need not be duplicated since at this point you will only be able to secure them from the interior edges.

Getting a matching taper on the extension tenons would be futile without a special cutter. I would just try to match the mortise bottom width. You may be able to match the bevel by tilting the table when routing or ripping. Two passes would be required since you need a square face at the outer edges. I really think attempting the taper is a PITA!

It looks like you are not actually matching the face of the extension to the face of the frame(not a single plane) so slight deviations will probably not be noticeable.

Anderson link worked for me FF 10.0!

[pennview]

Not sure exactly what profile you're trying to match, but you could contact these folks -- http://ridgecarbidetool.com -- as they can make you custom shaper cutters or router bits that would match whatever you need.