I'm currently laying out my first diorama. I have core board for the inside, balsa wood to support the inside, and i plan on using plaster of paris for the outside of the building. I have a couple of questions though. For a brick extiror, what is the best way to lay out the pattern fo the brick? should i carve it, or is there a different way to do it. And what is a good way to put the mortar color in between the bricks?

Glad to have you joining the ranks of the Diorama Maniacs.... Welcome aboard.

Plaster if fine, but if your can find Durham water putty you might check it out. Works just like plaster, but ( IMHO) it is easer to carve, & sands and a lot stronger that plaster.

As for bricks: I simple lay it out with a ruler or I use a template that I made from styrene that is the width of a 1/35-scale brick. Using my carving tool I cut in the horizontal line then cut in the vertical lines...





Check out the great article here at Armorama for other ideas. My article, Basic construction of Walls - Hunter or Hunted , might be helpful

As for mortar, I generally use a black or dark burnt umber wash (or Prussian blue if I am going to do a winter scene with ice and snow) wash and then dry brush the brick for contrast. Remember in 1/35 scale, the mortar is hardly seen. Considering 12 inches = 0.3428571429 of an inch, a ¼ to 3/8 inch layer of mortar between bricks is only 0.007142857143 of an inch... hardly seen by the human eye in scale.

John
www.johnneill.com

I read it somewhere that you can do a wash using your desired mortar color. After washing immediately wipe away those on the brick....by doing so, only the seams/mortar will retain the color....

Another option to doing the wash is to paint the entire thing in the mortar color. I'd vary the color here and there to keep it from looking monochromatic (one solid color) then go back over that and dry brush the brick color, again, varying the colors used. HTH "Q"

Yes in my opinion this is the best way to do it. Sometimes if instead of a thick wash you apply several thin ones you don't even need to wipe anything off. Added benefit of doing it this way is that the wash also dulls the color of bricks themselves giving them a nice aged look.

Wall spackle will work too. Same techniqes as above just different material
I used a razor saw as my scribing tool for the long lines. It got them nice and uniform and it was a bit easier to keep them straight over longer distances.
I used a dental scribing tool for the short lines.

I used plastic template that I made to scale after measuring a brick from the house.

Definitely use a number of different shades of your brick color to vary them from place to place.

Best thing to do is take notice of house while your drive around (be the passanger you don't want to crash into someones house )
See what colors there are and patters around windows and doors etc.
Check out the transition from the ground to the roof around doors and windows. etc.

Thank you for all of your help and suggestions but i've also got one other question. Will it be really noticeable if i use a 1/36 scale on the buildings and 1/35 scale on the models?

No. Bricks are not all the same size and the difference between 1/35 and 1/36 is next to nothing.

How i normally do walls is to scribe them into cast blocks of plaster. I use the pre-sized plastic strip method as well for size. I prefer casting the blocks and working on the flat rather than trying to scribe walls already in place. The big advantage with castings is .. if you are going to show ruins ... the damaged ends are much easier to convey and show the side veiw bricks as well!
I paint them all with the same brick colour .. by airbrush. then I use the base colour and add different colours to it and pick bricks out at random. Good colours to use are flesh, desert/dark yellow, orange, earth. Then paint the occasional brick with pure flesh, pure dark grey and pure dark brown. When finished and dry I add a filter or two to blend them. The mortar I give a dark wash first to define, then use a very light grey oil and pastel mix. The pastel is great for this. I wash in the lines as close as possible but over spils can be brushed out over the area to show weathering and is quite natural also.
When dry this wall can be futher weatherd by green at the bottom and even if the roof has growth, green water lines look great. Dusting near the bottom adds a nice effect also!

Another option instead of scribing is to buy already prescribed plastruct sheets. Easily fixed and window and door detail can be added with plastic strip and every fixed with your normal cement. This method is great for lots of fine detail. The following picture is by carlos Elias (spelling?). A master dio builder IMO.

Another method Carlos uses and something Ive been trying out is using cork to cut to shape, and then build almost like its done in real life. This is great for more complicated buildings. below is one of carlos´s in progress and the 1/16 figure and wall was my first attempt at this method.