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Installing Replacement Windows Part 3 of 3

Because I picked a nice, sunny and warm day, I didn’t have to work as quickly. I can tell you from my experience that installing windows during a sub-30 degree weather is definitely not my idea of fun or recommended.

TIP: If you HAVE TO to install replacement windows during this type of weather, I would recommend that you warm up some caulking tubes before starting the project.

Moving right along, the following steps will be covered in this section:

  1. Prep the new replacement window;
  2. Test fit a new replacement window;
  3. Apply caulking to the window opening and replacement window
  4. Insert, level and plumb new replacement window using shims;
  5. Install screws and finish plugs;
  6. Double check the level and plumb;
  7. Clean up.

Step 7- Installing a new Replacement Window

Step 7.1 – Prepping the replacement window

Carefully remove the shrink wrap (ensuring that the screen doesn’t get cut) from the window and bring it, the screen, screws, and other materials to the work location.

Sit on the floor with the bottom section of a replacement window resting on your legs. This step ensures that the window has a soft surface to dissipate the banging motion when installing a sill adapter.

Position the sill adapter, and starting from one side, tap on it with a rubber mallet to attach the sill adapter channel to the replacement window frame.

Drill two weep holes (one on each corner of the sill adapter) using a 1″ drill bit, making sure the hole was close to the bottom edge of sill adapter (follow the manufacturer’s recommendation). These weep holes prevent the sill adapter from pooling rain water, which can potentially rot the window sill if not properly drained.

Step 7.2 – Test fitting

Test fit the replacement window (again) to make sure that everything lines up. This step will ensures that I catch any remaining debris or protruding nails that I may have missed earlier. Then, check to make sure that the replacement window is level and plumb.

To check the level (true horizontal), use a torpedo level (12″ length) and measure 3 spots:

  1. Top window frame;
  2. Top of the bottom sash;
  3. Bottom window frame.

window-opening-componentsIf the window is not level, remove the window and temporarily install a short piece of shim at the suspect corner (see picture with red arrow for location).

Re-insert the window and re-check. If the window is now level, remove the window and glued the shim in place with some caulking.

TIP: When I first started replacing windows many years ago, I used to hurry along and accepted less-than perfect window levels. BIG MISTAKE! Take your time and do it the right way!

To ensure that the new replacement window is plumb, I place a torpedo leve (or 4 ft level) against the window frame in two ways as shown below:


Both measurement should be plumb; In rare cases, I attach small shim pieces against the exterior blind stops to remedy this issue.

Step 7.3 – Caulking

My preference is to use Phenoseal caulking from DAP. I’ve always been successful with this brand.

First, take a damp rag and wipe off the window opening perimeter to eliminate any dust and particles. Let it dry for few minutes.

In the meantime, cut off caulking tube’s tip about 1/4 inch at a 45 degree angle. This ensures that caulking bead will be evenly applied. Using one smooth motion, apply a continuous strip of caulking bead around the window opening, including the edge of the window stool.

Step 7.4 – Replacement window installation

Carefully insert the new replacement window, taking special care to not smear the caulking beads, by tipping in the bottom section first (just over the stool) then up righting the window into the opening.

TIP: If you are working alone, get a cordless drill belt clip (around $5-10) and have the cordless drill and screws ready BEFORE installing the new replacement window.

Then, insert shims around the perimeter and temporarily secure the window by installing 2 screws at the top (one on each side). Adjust the retractable screws (one on each side of the window, located usually at mid point), then re-check and re-shim if necessary, to make sure that the new replacement window is truly level and plumb. Finally, install the two bottom remaining screws.

Upon completion, check the window operation by moving both sashes up and down. Both sashes should move relatively with ease; if they bind in any way (e.g. sash frames rubbing against the window frame), play around with adjustable screws and/or shims until the problem is resolved.

Finally, lay down another bead of caulking around the window from the inside, then re-install the interior stops (a.k.a. quarter-round molding).

That’s it! Now you have installed your first replacement window! Wasn’t that easy?

I know these steps seem very difficult at first, but you will get better at it after installing one window after another. When I started out I felt the same way. After replacing many windows over the years, I now feel comfortable replacing any windows. An important thing to remember is to TAKE YOUR TIME!

Good luck with replacing your drafty windows with new replacement windows!

Installing Replacement Windows Part 2 of 3

Sunday 12th of February 2012

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