How to build a lean-to glasshouse
Step 9. Paint it
Paint it all
Now with all the sections made, slop on a coat or two of paint prior to the frames being assembled.
A good sealing of paint helps protect the glasshouse from the elements, and by putting on a coat or two prior to assembly means all the sections can be coated in their entirety. Once assembled, and prior to the glass being fitted, another coat can be applied.