I had a couple estimates from 2 well known window manufacturers here in Minnesota.WOW, are they proud of their windows! Anyways, I think I'm going to tackle them myself, thought I'd do one that people won't see to start.

A couple questions.

1. How do I know what to order for jamb extensions?

2. One of the windows I'm looking at has aluminum brick mould available in various shapes. I sure like the maintenance free option of this. If I choose another manufacturer is there another way to use aluminum brick mould?

 

As for the jamb extensions, I never get jambs from the window company unless it's a wood Andersen window- their jamb extensions are tongue and groove and have preinstalled pocket screws. Jambs are usually something you can make yourself. The width depends on the thickeness of the window you will be installing, the manner (the depth) it is being installed, and the wall thickness of the existing wall.

If you know all that ahead of time, you could get and prepare the jambs. But in many cases it's a good idea to wait until the windows are installed, THEN measure the trim needs, since something unexpected could change the way the window may be installed.

When we prepare trim ahead of time we usually make the jambs extra wide and cut them to the exact width on site, after the windows are installed.

Jmabs can be made of many types of material, depending on your trim needs and whether the jambs will be painted or stained... MDF, veneered plywood, clear pine, fir, oak, or you can buy door jambs and rip them to size. It just depends how you want to trim them.

As for the other question, I've never heard of aluminum brickmould. I hope the windows you get won't be aluminum (not appropriate for Minnesota winters!)

Some vinyl windows have vinyl brickmould as an option that can be preinstalled on the windows you order, but that varies from brand to brand.

 

Xsleeper,
Thanks for the reply, great information. We are going with wood windows, aluminum clad. One manufacturer has aluminum brick mould available.
The house is only 12 years old, and poor quality windows were put in. The walls are 2 X 6, and there's 1/2" sheetrock on the inside. Does that make it any easier to figure out what jamb extensions to get? I'm starting with just one window to see how it goes. I've installed windows in new construction, but never replaced windows.

 

The only additional thing you need to know to determine your wall thickness is the size of sheathing used. The easiest thing to do would be to remove a piece of window trim from one of your windows and stick a ruler or framing square back into the rough opening until you feel it hit the nailing fin. Since you have 2x6 and 1/2" drywall your wall thickness should be between 6 1/2" and 7", depending on what was used for sheathing.

If you'd like to have the jambs factory installed, when you order your wood windows you can usually tell them what the wall thickness is and they'll either shoot them on or include them. Otherwise, I would assume that your windows will be made for a standard 4 9/16" wall, and you're extension jamb would be the rest... somewhere in the neighborhood of 1 15/16 - 2 7/16".

Assuming that your new windows will have a nailing fin, they will install just like new construction windows would. Only difference is that you now have siding and trim to fight.