I’m getting ready to install the 1 X 4 Hardi trim around all the windows on the new house and I have a question on the layout.
We’re looking for the arts & crafts look, so I know the head casing will extend beyond the side casings by about an inch on each side. However, for proper water shedding, should the sides run past the bottom piece, or should they die into the bottom casing.
The material is all same thickness, so there shouldn’t be any areas of pooling.
On the the interior, it’s a no-brainer. The top and bottom rum long and the sides are in between. I’m just worried about the exterior application.
Should I be worried?
Thanks! Jim
Replies
Die into the exterior sill.
Consider using a cove molding under the exterior sill and a crown molding at the head casing as well. These are typical A&C treatments.
Regards,
Scooter
"I may be drunk, but you're crazy, and I'll be sober tomorrow." WC Fields, "Its a Gift" 1934
Maybe the attached sketches will help describe what I'm after. Is method "A", the "die" method preferred, or method "B", the "run past" preferred?
Thanks!
B is the perferred method if you live in a wet climate - you want the water to run down the front on the seam, as opposed to across where it can wick in easier.
Also, I would put a sill on it as well at about 15 deg.
Here's a sketch of what my exterior window trim does. It's a little more complex, but the look is right to me.zak
"so it goes"
Hey, Zak, you are using Sketchup! I am wasting a lot of my life right now, obsessing with learning it.
Other than modeling window trim, what are you doing with it?
Hey Gene-
So far I've just used it for drawing up my attic remodel plans. I've been thinking I'd like to do a few other things, sketch out some houses or something. I don't really have a need for that right now though, so we'll see if I get around to it. Your drawings look great, it looks like a good tool for you.
View Imagezak
"so it goes"
Die, but during that era you would have had a proper windowsill that projected beyond trim and sloped about 10-12 degrees.
If you want an authentic look, do what Snowmon said and add a sill. "Picture framing" a window is for contemporary NeoCraftsman buildings.
Work from the original time period typically had a 1x6 head, 1x5 (side) casings, and a 2x sill at 10 degrees (sloped to shed water). You can dummy this up on a modern window by ripping some 2x stock at 10 degrees (you'll end up with a paralellogram in cross-section); secure this to the sheathing with some countersunk screws. Let the sill project about an inch beyond the face of the casings. If you want, you can cut a rabbet into the bottom of the sill, into which you can tuck the siding.
An exterior apron (piece under the sill) can, in fact, be found in original work, but it's not as common, nor is a cove or other trim piece. Functionally, the sill is supposed to act as a drip edge (many sills have a drip kerf cut into them as well). Adding aprons or additional trim elements can hinder the action of the drip edge somewhat.
Of course, it's your house, and you should just choose whatever style you prefer.
Work from the original time period typically had a 1x6 head, 1x5 (side) casings, and a 2x sill at 10 degrees (sloped to shed water).
A better technique (found on my original 200 year old house) is:
(1) Hand moulded/planed drip cap extending 1" or so out over head casing. Can be farther especially if you want to use small crown moulding under the extension.
(2) 1+1/2" x 5" or 6" head casing with rabbetted 3/4+"x5" rear side slots for pre-painted side casing to slip up into
(3) the 3/4"x 5" side casings mentioned above with proper bevel cut for mounting on sill
(4) the 10-15 degree sloped 1+1/2"-2" sill
All wood was eastern white pine for paint retention qualities. All wood pieces should be painted on all hidden surfaces twice before installation. That hadn't been done on my place and is a recent recommendation. Stops any leaked water from wicking into wood where rot may start.
The best thing about this system- no caulking and flashing used and will last 200+ years if maintained well.
A better technique (found on my original 200 year old house) is...
You're right about these techniques -- they will result in a superior product. Being on the west coast, I haven't seen many of these older techniques (the rabbeted head casing which receives the side casing is a good idea I've never seen, for example). By the time of the Craftsman-era houses, some shortcuts were already being taken by builders.
Despite the obvious functional benefits, most Craftsman houses didn't have drip caps over the window and door heads simply because it didn't fit the style. However, the heavy rakes and eaves on Craftsman houses often protect the window heads so well that they rarely see water anyway. My 1911 house has three-foot overhangs; you can usually stay dry even in a heavy rain by just staying close to the house.
Otherwise, I suppose that simply flashing the window heads would be the best approach these days. It would definitely improve the durability of the construction while still conforming to the style visually.
Caulking, all caulking, will eventually fail and anything we can do to prevent water from getting past is worth it.
Whatever design you choose, there shouldn't be any horizontal surfaces that won't shed water. Even a small bevel on all surfaces will go miles towards sheding water.
I've never tried to bevel hardi trim, but beveling all horizontal surfaces at least 7 degrees is probably doable, albeit messy.