shimming concrete window sill to level
Hello All,
I’ve got an existing brick wall that was constructed on a slightly sloped carport slab. As a result, the top of the brick wall is drops about 1-1/4″ over 20′. The wall is not full height; it is about 7′ tall. Above is open to an existing roof.
I’m planning on enclosing the open space above with a window wall. I will be attaching a (shimmed-to-level) sill plate to the top of the brick wall to serve as the base for all the wall framing and window installation.
I’m also planning on installing a continuous run of precast concrete sills (several 4′ lengths) along the entire 20′ length of the wall, under/just in front of the lower windows. The sill will overhang the brick wall by 2″.
Question is, how do I set the concrete sill level? Ideally, I’d like to maintain a consistent gap between the windows and the sill to fill with backer rod and caulk.
As is, I’d have 3/8″ mortar on the high end, and 1-5/8″ at the low end. This is probably not advisable for structural and aesthetic reasons.
Any suggestions for a structurally sound and visually appealing solution? I’ve attached a drawing for reference.
Many thanks again.
Best,
Andrew…
Replies
Whatever you do to "level" the sill will show up on the brick. I take it the roof is already in place? does it run with the top of the brick or is it on a level plane?
If roof level, I'd be tempted to make up the distance up top of the sill-each window opening taller than the one preceeding. Shouldn't have to cut the glass on a taper, just bump up the size each section.
If using stock windows in an assembled frame-I'd think of shimming them at the sill and the same up top-rip the head casing or frieze (whatever) on a slight taper, each section.
Probably I should look at your sketch.
edit: Stock window. What do you think about making up a bit of it on the mortared sill, some more on the framing the window "sits'' on, the rest on the head? Getting up that high the only real dead giveaway spot would be on the morter joint between brick and sill.
Is the inside finished out to a room? That might screw with you a bit if all the glass would be wanting to run level. How bout pouring your own concrete sill and thicken that up.
Man, no quick easy and right answers from me. Sorry. Best of luck.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Edited 12/2/2007 3:06 pm ET by calvin
The roof is indeed existing. It is a shed roof. Here's an attached pic of the wall elevation showing the windows and framing. This drawing shows the concrete sill sloped, which would result in an uneven gap between the window sill and the concrete sill.The only other thing I could think of was finding a concrete sill that lipped the front. This would help to hide the uneven mortar joint. Even so, would 1-5/8" of mortar be too large to hold properly?Hope this helps.thanks.Andrew...Edited 12/2/2007 3:15 pm ET by kleinchen
Edited 12/2/2007 3:15 pm ET by kleinchen
Is the roof line level along that 20'? or does it run parallel to the brick?
I'm no mason, but would strike a level line with maybe a sand mix to give you a level bed from out just away from the hight point. After that sets, morter the sill down to that. Easier to lay those sills to something close to level. That doesn't give you the answer you're looking for as far as hiding the joint.
I'd give serious thought to pouring my own cap dead nuts level on top for the windows. Fudge (cheat) the view line of the tapered sill at the brick.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Interesting idea to pour the sill in place as a unit. It would be cheaper in materials, but a bit more labor for the form work, etc. In any case, it's probably the best solution so far.If it were to cover the entire top of the wall with a 2" overhang along the exterior side, that would make it roughly 10-1/2" wide x 3" high, perhaps tapering down to around 2-1/4".I'm no mason either (stating the obvious), but I suppose I could epoxy some threaded anchors in the mortar on the top of the brick wall, perhaps create a matrix of wire reinforcement, and pour the concrete on to that to tie the two together, and strengthen the top of the wall too.I assume I'd still need to seam it at a couple spots along that 20' run. Any idea what a good breaking point would be? A seam every 5' would roughly tie it in with the windows above.I'm having someone do some concrete slab work anyway, perhaps I can work this in too.Thanks fro the idea.Best,
Andrew...
Breaks at the window's would make sense. Running some rerod along this "bond" sill would be a potential, but still control joints either formed or scored.
For a thermal break I would not run the formed sill all the way inside to the living space. I'd probably take it just under the outside edge of the window, install a sill pan under the window, on top of the wood framing, that would lip over the concrete.
Man, there's alot of detailing on this thing. Somebodies got to have a better and simpler idea.
Best of luck.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
How bout a chalk line and a masonry blade?
Looks like that wall is at least two bricks wide. A gas powered portable saw with a 12" blade will cut the depth of that outside course of brick. I've done it on block foundation walls that were seriously out of level or had som big humps in them.
That presents other problems with the inside though, doesn't it?
Maybe a copper cap over a slushed to level gout bed, then the sill stone, plate and interior are all settin on the same plane. The copper cap would make a nice interior and exterior trim detail. The brick would lok tappered, but you wouldn't see a big hoggy motar joint under the sill stone.
Just tossing things out.
Maybe brickie will come along and see this.
Dave
The real challenge of the remodel-making it look right but looking like you haven't been there.
Anything's possible with enough time and money. Usually not enough of either.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
If the concrete sill overhangs enough why not just install a piece of trim under the sill to cover the tapered gap?
Let's not confuse the issue with facts!
i run into this alot dealing with 100yo buildings... set a string and go ahead and lay in your mortar to level up what you have... it is what it is... and it won't look that bad by the time you get your 2" overhang it might just look like a shadow... lay in your mortar 3/8 to 1/2" low... let it get hard... now you have a level surface to set your cast sills.... i cast and use full sills ie: i cast em usually 12" wide for my use and set my doors or windows onto them... 12" for my use leaves them usually 1.5" short where i place a piece of ripped 2x to the inside... glued to the back side of the sill and the threshold covers the transition from concrete to wood...
i use sheet metal molds to cast them... white portland and white fine sand... look like stone if i do it right... i do a slight cut on the bottom about 3/4" in from the outside overhang edge about 1/4" deep... makes a drip edge...
p
holy smokes! that's a lot of ideas. Thank you all.
Seems like laying a tapered bed of mortar to cap the wall may be the simplest fix. Cleverly concealing it with trim or shadows is the trick. I was also thinking that the shadow line of the overhang might conceal the unevenness of the grout line. Maybe that is enough.
Assuming I use a narrower sill designed to sit in front of the window wall (and the windows rest on wood framing), would it make sense to first level the entire top of the wall with mortar? Under the wood framing too? As it stands, I will have to shim the mud sill level anyway. Or is there some reason why mortar (on top of brick) would not be advisable under the PT mudsill?
Thanks again.
Best,
Andrew...