Since I am already working on the tower room, I decided to go ahead and begin the flat roofs. I am going to sandpaper them rather than just paint them.
You first need to paint the edges of your roof, install your already painted roof trim and prime your roof. I primed my roof with the same dark brown paint of the roof trim.
You might be tempted to add the sandpaper to your roof before your roof trim goes up but I don't recommend this. If you ever need to remove the paper, it will be glued under your trim and you will have to break your trim off, etc. You also don't want paper between two areas that should be glued flush together, especially sandpaper, so I suggest you cut your sandpaper around your trim instead. This is why you should prime your roof in the same color as your trim so it camouflages any miss cuts.
Make a paper template of your roof first and then cut it out on your sandpaper. You will need to join areas. Try to keep your joints confined to long, straight areas only. I marked in red where I joined my sandpaper in the photos below.
Join, do not overlap. Sandpaper does not overlap well and your joint lines will be more visible if they are overlapped. You just want to butt your joint edges to each other, as close as you can get them.
If your sandpaper has a thick rubber backing, like mines, you can use tacky glue to adhere it but if it has a paper backing, I recommend hot melt glue. You do not want sandpaper to warp with moisture from glue. It will cause your joint lines to really be highly noticeable. You also do not want glue to go through the paper and create a stain on the rough side. Sandpaper can not be cleaned. You will have to rip it off and start all over again and this is why I don't recommend for it to be glued under trim.
After the sandpaper was cut in place and it looked correct at the joints, I applied tacky glue, sparingly to the back, and glued it in place. You will need to use clamps to keep your joints down flat until dry. I used some square pieces from the dollhouse kit and then put handheld weights on top of them until it dried overnight.
Most of these flat roofs were gravel back in the day and sandpaper gives you a gravel look and rough texture to match. I chose a brown sandpaper to match the exterior colors of my dollhouse but you can use black sandpaper to create a more realistic gravel roof.
The lighter color sandpapers can make any markings on their backing paper visible through the front. Because of this, the darker the primer color you use, the better. Thankfully my roof trim is dark brown so it worked well to hide any markings that might want to show up through the front. If you don't want to deal with this obstacle, use black sandpaper. If you do choose a black sandpaper, purchase the highest grit they have because light and medium grits have a tendency to show the slightest scratches or marks. Black sandpaper can be damaged more easily than other colors.
Sandpapered Bay Roofs
You apply the sandpaper to the porch roof in the same way you do for the large flat roof.
When applying the sandpaper to the bay roofs, they must be installed on the dollhouse first. Then make a paper template of the roof and transfer that to your sandpaper, after you have achieved the perfect fit. Whether your sandpaper has a rubber coating on the back or is paper, you must use hot melt glue to adhere it to the bays. The curve of the bay roofs will not allow the wallpaper to lay flat until the tacky glue dries and there is no way to clamp it down without shifting or possibly damaging the sandpaper.
If your sandpaper has a paper backing, hot melt glue on the low setting is fine but if it has a rubber backing, then you have to set your hot melt glue gun to a high setting or your sandpaper will keep popping loose.
Keep In Mind
For an added touch of realism, sprinkle tiny pieces of white glitter on your sandpaper to make it look like glass on your gravel. Use it sparingly and it does not have to be adhered in any way. The rough texture of your sandpaper will hold it permanently in place.
If you need to touch up your roof trim, do it carefully because if paint touches your sandpaper, you will need to remove it and start over. Sandpaper is easily damaged and can not be repaired. Whatever area becomes damaged, must be removed in its entirety because unlike wallpaper, sandpaper can not be patched.
Sandpaper can also be painted but not after application so do all of your painting beforehand. Painting sandpaper that is already in place will cause it to permanently warp. Painted sandpaper that's already been applied can be easily repaired later if it ever becomes damaged with stain because you can touch it up with the same paint you painted it with. Just don't paint all of it all over again. Touch it up only.
