If your Ladue house has a mansard, the roof you are pricing is really two roofs that share one outline. The lower face is steep, often close to vertical, and it sheds water quickly. The upper section is shallow or nearly flat, and it sheds water slowly. Each part wears differently, takes different materials, and needs a different install sequence. A quote that lists one roof area and one price hides most of what you are paying for.
Older Ladue houses often had the mansard from the original build, and the roof detail around it was rarely simple. The steep face usually runs above a second floor, the top sits behind a parapet or a low wall, and the gutter may be hidden behind the wall line. Before you compare numbers, know where the water is supposed to go at each of those points.
Where the break line decides the leak
Where the steep face meets the shallow top, the roof changes direction. That is the break line. Water coming off the upper section has to cross it and then keep running down the steep face. A break flashed with the wrong sequence or the wrong metal will let water in beneath the surface, and the first sign is often a stain on a ceiling below the wall, not on the roof you can see from the yard.
Every corner of a mansard adds an angle. Where two faces meet on the outside you get a hip. Where they meet on the inside you get a valley. A mansard with four corners carries at least four hips on the steep face, plus the matching valley work where the upper section turns. Ask the crew how many of each the count assumes, because the count sets the metal, the labor and the time on the ladder.
The break also collects leaves. Maple seed and oak debris pile up in the crease where the steep face meets the shallow top, and the pile holds water against the flashing through a wet week. Clearing it is a maintenance task, and it is also a reason to ask whether the new flashing includes a guard or cover at the break.
Town roofing
Ladue lots are large and the houses sit back among mature trees, so a mansard reroof is usually a longer job than the square count suggests. Limbs can come down on the steep face after a wind event, and overhanging branches drop needles and seed pods that work into the seams. Keys documents the existing condition with photos and measurements before any tear-off, and puts the written scope with those photos in your hands before the crew starts.
The St. Louis freeze and thaw cycle works on a mansard differently than on a simple gable. Snow on the steep face slides off in sheets and lands on the gutter or the ground below the wall. In a thaw, the meltwater runs back under the lower edge. Ask how the quote handles the drip edge at the bottom of the steep face and which component catches the water that comes off it. The answer tells you whether the gutter line below was included in the scope or left for later.
Hail season in St. Louis County runs through spring and into early summer. A steep face takes hail differently than a flat section, and the dents show on the windward side first. Photograph the steep face and the upper section separately, with a tape or ruler in frame, so the file shows which face took the impact. Keep those photos with the scope. Missouri law (RSMo 407.725) bars a roofing contractor from representing or negotiating a homeowner's insurance claim, so any conversation with your insurer stays with you, and Keys attends the job as the contractor.
Permits are a separate step. Municipal permit desks across St. Louis County do not all treat a reroof the same way, and a mansard can raise questions about structure, the parapet and the height of the work. Confirm with the city which permit the job needs before a crew arrives. Ask the contractor to name the permit on the written scope and to say who pulls it.
Staging is the other site question. Working the steep face from a ladder is slow and unsafe, and the crew will usually need a stage, a boom or a lift to reach the break. Ask whether that equipment is in the price, whether it appears as a line with a number, or whether it is left as an allowance. An allowance is not a price, and it moves the total after you sign.
What it costs
A mansard quote should be priced by section. Ask for the steep face, the shallow top, the hips and valleys, the break flashing, the drip edge and the staging as separate lines. Two quotes can look far apart while describing the same roof, or look close while one leaves the break flashing out entirely. The totals only compare when the lines match.
Materials differ by section. The steep face is commonly shingled, and the shingle has to lie flat on a near-vertical pitch and be installed to the manufacturer's steep-slope instructions. The shallow top is usually covered with a low-slope system, and that system has its own underlayment, seams and terminations. A quote that names one product for the entire roof has not described the roof. Keys installs Atlas and Malarkey shingles only, so any shingle line in a Keys quote will name one of those two brands.
Ask for the membrane or underlayment product by name, the number of layers, and the seam method. Ask whether the price includes the metal at the break and the corners, and whether that metal is listed by gauge and finish. If the quote says flashing without saying what the flashing is made of, the quote is not finished yet.
Plan for the work to run longer than a simple gable. Steep-face work is slower, the crew changes tools at the break, and the staging has to come down and go up again if the weather turns. A schedule that assumes one pace for the whole roof will be wrong on the day the crew reaches the mansard.
What to ask
- Which line in the quote covers the break flashing, and what metal or material does it use?
- How many hips and valleys does the count assume, and where are they marked on the scope?
- Is the steep face priced at full height, and is staging included or left as an allowance?
- What product covers the shallow top, how many layers go on, and how are the seams made?
- Where does the drip edge sit at the bottom of the steep face, and what catches the water below it?
- Which permit does the work need, who pulls it, and is the permit number on the scope?
- Who from Keys is on site while the crew works the steep face, and how do I reach that person?
Put the answers in writing before you choose. A verbal answer about the break flashing is not part of the contract, and the first time you need that answer will be after the tear-off. Keys puts the written scope, the photos and the measurements in the homeowner's hands before the first nail, so you can compare the sections against each other and against the other quotes you collect.
For questions about a Ladue mansard, call the Keys office at (314) 220-2333.