Alright, now you can stand back and see the perfect circle in your square tray. I know it seems strange to have the blocks sticking out like that, but it is a lot easier to nail the blocks in before the ring is hung.
The last step completed was cutting the top plate to act as our backing as the struts are put in place.
Step 5 - Hanging the #1 and #2 Struts
All the struts are labeled "strut" and have a number on the nailing face. There will (2) #1 struts and (2) #2 struts. Place the #1 struts so the ends butt together and are centered on the top plate. Nail them in place. Now lift the three connected pieces into the opening and rest them on top of the outer ring. Center the struts against the center marks on opposing sides of the framed box, check plumb and nail into the box sides. Place the #2 struts so they butt perpendicularly to the #1 struts. Check plumb and nail into the top plate and the framed box.
Step 6 - Install #3 and #4 struts
Now that you have the experience of hanging the #1 and #2 struts, the #3 and #4 struts will be pretty easy to put in place.
The #3 and #4 struts will be long.
Take (1) #3 and put it in place, between any #1 and #2 at a 45' angle. It WILL hang over the back side of the outer ring. Mark the #3 at the point of contact with the outer ring. Draw a line across the face of the arch 1 1/2" below this mark on the end opposite the #3 label. Cut off remaining material and discard. Use this as your master for sizing the other #3 struts. Nail all #3 struts into the top plate.
Take (1) #4 and repeat the steps above. You may need to use shims between the strut and top plate (or a larger top plate) depending on the size of your dome.
Now you are probably asking yourself how to keep the struts in place for dry wall.
Step 7 - Securing the Struts
Nail all the #3 and #4 struts to the back of the outer ring. Add some blocking to the back side of the struts for added structure.
Step 8 - Installing the light ring
Take the Light Ring pieces and line them up with the seams on the outer ring, check flush (plumb) and nail them into the previously installed blocks. We would recommend that you always secure the top plate to a bridge built across
the top of the dome. Use a pair of knee walls and a box beam to assure
stability and to support the weight of a light fixture or
Now, admire your newly installed dome. If you plan to hang a light fixture or want added structure and stability, build a bridge across the top using two knee walls and a box beam. This way future homeowners can hang a light with a winch, confidently.