A Pictorial Guide to Window Trims and Mulling
What are reinforcement window trims?
Heavy-duty reinforcement window trims provide enhanced stability to fully support heavier windows that are mulled together. This pictorial blog provides step-by-step guidelines on how to mull windows with these reinforcement window trims.
What are mulled windows?
Mulled windows are two or more separate windows joined together to fit into a single wall opening. To do this, mulled window sets must be permanently attached together during installation. When combining or joining windows, we use reinforcing trims or mull strips along with our proprietary interior and exterior accessory pockets. These pockets are included as a standard item with all Ringer Windows. Lastly, very large openings with multiple connected windows may require special heavy duty reinforcement parts.
How do I order windows with reinforcement window trims?
When ordering, it is imperative that you inform your Ringer representative about windows to be mulled together in single openings. This will ensure that window mulling and appropriate window trim costs are included in your original bid. Your representative will also help you to determine whether you need regular or heavy-duty reinforcement parts. Reinforcement window trims may be ordered with any of our window products including stock windows. Once the proper mulling parts are identified your window order will contain all required components. This includes reinforcement metal if required, 1/2″ or 0” mull trims or strips, and L-Brackets to strengthen your mulled window installation.
Will I need any additional hardware or accessory window trims?
In addition, replacement window installations may need special Vin-L-Hold fasteners or other unique accessory window trims. These additional trims and parts may be purchased from us. Once again, please communicate as many details as possible about your window installation to your Ringer Windows representative. This is essential for us to accurately quote the parts needed for your particular application!
Please refer to the section entitled “INSTALLING MULLS USING REINFORCEMENT WITH A 1/2″ STRIP” in our mulling instructions.
A three window replacement installation in brick was used for this description and pictorial guide. The three window set was placed in a 12′ x 7′ opening.
Part A. Prepare the Opening
STEP 1: (For New Construction) Frame Opening and Prepare for Window Set
Use Ringer Windows new construction install guidelines for installing new windows. Prepare the new framed opening for installation of mulled windows.
STEP 1: (For Window Replacement) Remove Old Windows
Use Ringer Windows replacement window installation guidelines for replacement windows. Remove old windows and caulk. Prepare window opening for new window installation.
Removing the glass of the old window
Removal of old glass and careful handling
Glass removal for large windows takes two people
Part B. Install Window #1
STEP 2: Plan, Measure, Mark Locations, Before Installing the 1st Window
Once the opening is prepared, the next window mulling step is measuring, marking, and remeasuring the windows and opening. This is because you must ensure proper fit in the opening using either regular or reinforced window mull bars and a 1/2″ mull. It’s also critical to know each window’s location and orientation within the opening. So, measure each window, mark its locations in the opening, and include the 1/2″ spacer for the reinforcement bar between them.
Throughout this multi-window installation, continue to measure and remeasure. You must ensure that all windows will fit within the opening with reinforcement mull hardware.
Finally, with precision measuring and marking completed, you’re ready to install the first window and secure it to the framing.
Plan, Measure, Mark, Measure, Mark, Plan
Measure and Mark
Mark 1/2″ intervals for reinforcement mulls
Setting Window 1 into opening
STEP 3: Align, Set, Plumb, Secure the Window and Measure Again
Window number one should align with the markings made earlier. Place it in the opening and align it with the edge of its marking. Check again for alignment and if it’s an operable window make sure it will open properly. Secure window number one to the building frame. Measure again.
Line up Window to marking
Measure to make sure Window 2 will fit properly.
Secure window to framing.
Measure and place window properly
STEP 4: Install the 1/2″ Reinforcement Window Mull Bar
Metal reinforcement bar(s) have been pre-cut for the windows that you ordered. Remove the blue protective backing on their adhesive strip on one side. Adhere the metal reinforcement to the open side of the already installed first window.
Remove Blue Protective backing from Metal Bar
Adhere Reinforcement Bar to Window 1
Secure Reinforcement Bar
Reinforcement Metal Bar
STEP 5: Install the L-Brackets
Fasten the L-Bracket to the window through the reinforcement metal bar and to the building frame. Two L-Brackets should be secured at the bottom and the top of the window.
Two L-Brackets for top and bottom of window
Attach Lower L-Bracker to window and house frame
Secure L-Bracket
Secure Upper L-Bracket to Window 1
Part C. Install Window #2
STEP 6: Installing Window Two
Once the L-Brackets are fastened and measurements are assured, window two is ready for placement and installation.
Remove blue protective strip on refo bar
Install Window Two
Place Window Two
Measure for Window 3
STEP 7: Install 1/2″ Reinforcement Window Trims or Mull Strips
After window two is placed, window one and two are connected with the special 1/2″ window trim or mull strip. This 1/2″ mull bar is one of the proprietary installation window trims available as part of the trim kit. Starting at the top, the mull strip connects the two windows together. You must trim the bottom of it to fully connect the 1/2″ mull strip to the windows. Lastly, once the windows are connected, secure window two to the building frame.
Attached 1/2″ mull strip to accessory pocket near top on both sides of window
Snap in half inch mull
Secure within the accessory pocket
Securing 1/2″ reinforcement mull into the accessory pocket
STEP 8: Trim & Fasten the 1/2″ Reinforcement Window Trim or Mull Strip & Secure the Window
Outside bottom of Mull strip
Trim mull strip to be able to secure top to bottom within the accessory pocket between Window 1 and 2
Completed reinforcement mulling of Window 1 and Window 2
Secure Window 2 after completing mulling to Window 1
Part D. Install Additional Windows & Window Trims as Needed
STEP 9: (For Second Window Installation)
If your window mulling is for a two window installation in one opening, your mulling is complete . Window trim-out (if required) and seal for replacement window installation are the final steps. You now have two successfully mulled windows.
STEP 9: (For Third Window Installation)
For more than two window windows in an opening, measure and check to be sure the remaining window(s) will be able to fit within the opening. Repeat Step 3 – 8 above.
A Short Summary of Window Mulling & Trims
Below is a brief pictorial summary of the steps shown above to mull windows with window trims. A three window installation was used in this example. Please note that after all reinforcement window trims or mulls are fastened, window installation can be completed. Lastly, please be aware that replacement windows may require additional insulation, accessory replacement window trims, and sealant.
STEP 3 – Plan/measure for next window
Step 5/6 If needed, Secure reinforcement bar, L-Brackets to open edge
Step 8: Secure Window to outer building frame
STEP 4 – Place and set next Window
Step 7/8 – Secure 1/2″ Mull Strip inside and out. Trim and complete
INSTALLATION OF THREE WINDOWS WITH REINFORCEMENT MULLS
Let Us Professionally Install your Windows & Window Trims
Window mulling is not complicated, but it does require good technical knowledge of how windows are installed. That’s why Ringer Windows offers full-service window installation for replacement windows in Austin area homes and businesses. Our in-house crews will provide the professional know how and superior service your replacement windows need. Contact us online or call today at 512-989-7000 to discuss our installation services for replacement windows.
Attach Metal Reinforcement Mull Bar Space – Video
