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Monday, May 8, 2017

The Time We Built a Roof Over the Greenhouse Window

If you've been keeping up with the previous posts (The Time We Planned the Yard and The Time We Built Concrete Planter Boxes) then you know how much I love to garden.  Well what do you do in the winter?  You want to have fresh herbs and such, but it's just too cold for things to grow!  Well, one of the reasons we fell in love with our Fixer Upper when we first bought it was the Greenhouse Window in the kitchen.  This thing is amazing and we love it! It's great in the summer to start our seeds in and it's perfect in the winter to keep our herbs alive.

Well, after the first summer in our home we realized that while the window is great at keeping plants warm it the sun beaming down into it caused a significant cooling problem in our Kitchen.  All summer long the sun just beamed into the kitchen, making it an almost unbearable room to be in.   We tried closing it off (to make it accessible, but sealed from the rest of the room, but that just made the humidity accumulate inside the window.  So we decided that this wonderful window needed a roof over it to help block some of the overhead sunshine in the heat of the day.  The window would still receive a great deal of morning sun and would stay warmer for our plants in the winter, but some of the brightest hottest sun of the day would be blocked, making our kitchen much more hospitable.

This window also had water problems that we needed to address.  Even after filling and resealing the wood under the window we were still having moisture problems in the siding below the window.  We theorized that rain was running down the window supports and saturating the wood causing the problem.

Thankfully, this turned out to be a great little afternoon project!  Here are the basic steps to building a roof over a greenhouse window:

Building a Roof Over A Greenhouse Window...
1.  Measure the window. This sounds obvious, but for the sake of our DIY followers I'll point out the need to measure the top edges of the window to make sure that you get adequate coverage and slope to the roof.
2.  Take off any trim pieces near window.  Our window had a piece of trim along the top edge that we wanted to use to cover the flashing at the top of the new roof.  So we removed it and set it aside to use later.
The trim taken down and the latter set up so we can measure the window.
3. Cut 2x4s to the dimensions of the frame for your roof.  Notice here how we made the outer edge come just outside of the window brick block frame.  We also made the slope of the roof frame steep enough that the bottom of the 2x4 would come to just above the brick block frame of the window (thereby protecting the top of the window).

4. Attach the frame to the Siding.  As you can see here, my husband attached the rectangular bottom part of the frame directly to the siding around the window.  He then attached the sloped 2x4s directly to the rectangular frame and the siding.
Constructing the Frame
5.  Prime and Paint Your Frame. This part is important.  You want to paint and prime your frame to match the trim of your window and house.  This happens now instead of at the end of the project because it is difficult to access the interior of the frame (which is visible from the kitchen) if the roof is in place.
Roof Frame is primed and painted.
6.  Measure Your Frame.  These dimensions will be different than the dimensions of the window.  Because you built the frame directly to the house you need to double check the measurements.  My dad always said "measure thrice, cut once".  

7.  Cut Plywood Board to 2 inches Larger than the Size of the Frame.  This will allow the frame to overhang roughly 1 inch on all sides of the frame.

8.  Paint the underside of the Plywood Frame Black.  This makes the reflective light less inside the room where the greenhouse is and allows it to be aesthetically pleasing from inside (you can see this area through the window).

9. Lay a Moisture Barrier Down on the Plywood.  This will help protect your plywood from rot.

10.  Attach the Plywood with Moisture Barrier to the Frame.  Screws are more reliable than nails, just make sure to get screws that are long enough to really connect with the frame.

11.  Place Flashing Along the top Edge of the Roof.  Ours is hidden behind the trim and runs about an inch under the shingles. 

12.  Attach Singles to the Plywood.  We used our nail gun to attache the shingles, but shingle nails would probably also work.  Just make sure that the nails do not go all the way through the plywood because they will show on the underside. Make sure to allow your shingles to overhang the edge of the plywood by at least 1/4".

The finished Greenhouse Window Roof!
14.  Reattach the Trim.  Take care to cover the top of the flashing and make sure to keep the trim lined up with the existing trim.  

15.  Touch up Paint As Needed.  It's inevitable that you will have nicked the siding a bit or that the trim will need to be touched up.  

Do you have one of these unique windows in your home?  What is your reaction to them?  Our Realtor seemed to think it was an "odd window" but we found it's character and purpose charming!  Share your comments below.


  1. Such an elegant yet simple solution, it looks great!

    1. Thanks Emily! And it has really helped a lot with our heating and cooling in that room!

  2. Such an elegant yet simple solution- it looks great!

  3. It turned out so great! Well done!

    1. Thanks Adrienne!! I'm afraid I can really only claim credit for the design, my husband did most of the construction! It was a great team effort, like most of our projects are!

  4. Wow I'm impressed! I know the window was practical but it's also just so pretty

    1. Thanks Alysse!! We really do love this window!! Check back later for updates about more work we did to this window!!