The order that arrives with no corners in it
Manufactured stone veneer is sold in two products that are priced and packed differently, and a great many first orders contain only one of them. Flats are the field stones and are sold by the square foot, usually ten to a carton. Corners are L-shaped pieces with a long leg and a short leg that wrap a vertical outside corner, and they are sold by the linear foot, commonly six to eight feet to a carton.
Because flats are quoted in square feet, the natural way to estimate a job is to work out the wall area and divide. That gives a flat count that is slightly too high and a corner count of zero. The wall then goes up beautifully until it reaches the first corner, where the flats butt into each other and show their cut edges, which no amount of mortar will disguise. Corner cartons are frequently the slower item at a supplier, so a shortfall there is a stop rather than a delay.
Corners take area off the flats
The second half of the correction is subtler. A corner piece does not only finish the corner; it covers real wall on both faces. Its long leg might run seven or eight inches down one wall and its short leg three or four down the other. So every linear foot of corner you install is a linear foot of wall you do not need flats for, on two elevations at once.
The convention is that a linear foot of corner replaces about half a square foot of flat area. That figure is a starting point rather than a constant, because it depends on the leg lengths of the particular stone profile, and profiles vary from a tight ledgestone to a big irregular fieldstone. If the manufacturer publishes the leg dimensions, add the two legs, divide by twelve, and use that instead.
Skip the subtraction and you overbuy flats by that amount, which on a house with four full-height corners is around eighteen square feet, or two cartons. Not a disaster, but the same arithmetic run in the other direction is what makes the corner count right, so it is worth doing properly.
| What you are counting | Sold by | Comes from |
|---|---|---|
| Flats | Square foot, boxed by area | Wall area less openings less corner coverage |
| Corners | Linear foot, boxed by length | Number of outside corners times their height |
| Sills and caps | Piece or linear foot | Window sills, wall caps, hearths, counted separately |
| Mortar | Bag | Scratch coat, setting bed and joints, each with its own rate |
Blending, and why the whole order comes at once
Stone veneer is coloured in production and pallets from different runs do not match exactly. The standard practice is to work out of several open boxes at a time and blend, so that any variation is distributed across the wall rather than concentrated in a band. That has an ordering consequence: a top-up order placed weeks later will very likely be a visibly different lot, and it will land in one area of the wall because that is where the work had stopped.
This is why the waste allowance on veneer is not really waste. It is the buffer that keeps you from having to reorder, and ten percent is a floor rather than a generous figure on a wall with many cuts, returns or a complicated opening layout. If the wall is a feature elevation, order the whole quantity in one go, including whatever you might plausibly need, and accept a few leftover boxes.
What is behind it matters more than what is on it
Adhered veneer is a heavy, absorbent, non-structural finish stuck to the outside of a wall. Water gets into it and behind it; that is normal and expected, and the wall is supposed to be built so that the water that gets behind can drain and dry. What handles that is the water-resistive barrier, the drainage provision behind the veneer, and the flashings at the base, at every opening and wherever the veneer stops.
Those layers only work if they lap in the correct relationship to each other, and a wall assembled out of order looks entirely finished and leaks. That failure is invisible from the face and shows up as rot in the framing years later, by which point the veneer has to come off to fix it. The correct assembly comes from the manufacturer instructions, from the drawings and from whoever inspects the work, and this calculator has nothing to say about it beyond urging you to settle it before the first stone goes on. The house wrap calculator and the flashing calculator quantify the materials involved.
Weight is the other consideration this page reports but does not judge. Whether the substrate, the framing and whatever the veneer bears on can carry it is a structural question with a code answer, and the answer differs by jurisdiction and by wall. If you are veneering a full-height elevation rather than a wainscot band, that question comes before the material count. For a real masonry veneer with ties, weeps and an air space rather than an adhered one, use the brick veneer calculator; for the mortar itself, the mortar mix calculator; and for a rendered finish over the same lath, the stucco calculator.
Questions people ask
How many linear feet of corner do I need?
Measure every vertical outside corner the veneer wraps and add their heights. Four full-height corners on a nine foot wall is thirty-six linear feet, which at six feet per carton is six cartons plus whatever the waste allowance adds. Do not forget corners that are not building corners: a chimney chase has four, a column has four, a bumped-out window has two, and a veneered band that returns onto a porch has two more. Inside corners generally do not need a corner piece, because flats can be butted into an inside corner and the joint is in shadow.
Is dry stack cheaper because there is no grout?
It saves the joint mortar, which is the smallest of the three mortar lines, and it usually costs more in stone and in labour. Dry stack has no joints to absorb variation, so every piece has to be selected and cut to sit tight against its neighbours, which is slower and produces more rejected pieces. It also has no mortar joint to shed water at the face, which puts more work on the drainage behind. Choose it because you want the look, not because you expect it to be the economical option.
Can I put stone veneer over an existing wall?
It depends entirely on what the existing wall is and what is behind it, which is a wall assembly question rather than a quantity one. Veneer is heavy, it holds water, and it hides everything underneath it permanently. Over a sound masonry substrate the stone can often be set directly. Over a framed wall it needs a water-resistive barrier and lath, and that barrier has to integrate with the flashings at every opening. Over existing cladding, you are usually looking at removal first. Nothing on this page decides that, and on an older house the removal itself raises a testing question about what the old materials contain.
What does the waste allowance actually cover?
Three things, in roughly this order of size. Cutting to fit around openings and at the ends of runs, which produces offcuts that are often too small to use. Rejection, because a proportion of any box will be pieces whose shape or colour does not work where you need it. And blending, since keeping several boxes open at once means you finish with partial boxes of every kind. Ten percent covers a plain rectangular wall. Fifteen or more is realistic on a wall broken up by openings, returns and a lot of corner work.
How accurate are the mortar figures?
They are as accurate as the coverage rates you put into them, which is why all three are input fields rather than fixed numbers. The variables are large: joint width can double the joint mortar, a substrate that is out of plane can double the setting bed, and stone size changes the linear feet of joint per square foot of wall by a factor of several between a large fieldstone and a tight ledgestone. Take the coverage figure from the bag you are buying, and when the count is tight, buy one more bag than the arithmetic says. Unopened bags return more easily than a stalled wall recovers.