A widow's walk is the small railed platform on top of a hip or low-pitch roof, the kind of feature a Ladue house uses to look out over its lot. Homeowners tend to think of the railing as trim. For the roofer, the railing is a row of holes in the roof, and each hole has to be framed, sealed and priced. If the posts are missing from the quote, the walk usually gets priced as though it were a sheet of shingles with a nice edge, and the difference shows up later as a leak at the base of a post.
What is actually up there
Most walks have a flat or nearly flat deck set into the top of the roof, surrounded by balusters or posts and a top rail. The deck sits on framing that is pitched so water runs toward a drain or scupper. It is covered with a membrane, not shingles, and the membrane is what keeps the rooms below dry. The posts or balusters are fastened down through that membrane into the framing underneath. Each fastening point is a roof penetration, and each one needs flashing that ties into the membrane around it.
That is the first thing to check on the walk itself. Ask the roofer to stand on the deck with you and count the posts, then count the drains, then write both numbers into the proposal. A walk with twelve posts and two drains is a different job from a walk with eight posts and one drain, even when the deck measures the same. If the proposal says walk and nothing else, you do not yet know what is being removed, reset or replaced.
Why the posts fail before the deck does
In St. Louis the freeze and thaw cycle works on every penetration. Water collects in the small gap around a post when the flashing is weak or the collar was set high. In a cold week that water freezes, expands, and widens the gap. In the next warm spell it runs down the post and into the framing. Owners often notice the stain on the ceiling of the room below long before they see any problem on the walk itself.
Ice is the other load. Snow sits on the deck and against the rail, and in a thaw it slides or drips, refreezes at the edge, and pushes water back under the membrane. A railing that was fastened with short screws into old blocking can work loose after several winters of that. When the roofer pulls up a post to reset it, the crew should look at the blocking underneath and the condition of the membrane around the hole, not just reinstall the post in the same spot.
The walking surface is its own assembly
People walk on the deck. They stand at the rail, carry chairs up, set down planters, and drag things across the membrane. That foot traffic scuffs the surface, and the surface is what the water runs over. If the membrane was chosen for a flat roof that nobody walks on, the traffic will wear through it sooner than the rest of the house will. Some owners add walk pads or a protective cap over the high-traffic path, and a roofer can tell you whether the membrane you are getting can take that use.
Heavy planters are a separate concern. A large pot of soil and water placed against the rail adds load at the post where it is already fastened into the least support. It is worth asking the roofer what load the railing connection is designed to carry before you decide where the planters go.
Guard height and the permit question
The rail is also a guard, and guard height is a code matter. The model code most jurisdictions adopt sets a minimum height for guards at elevated walking surfaces, and many local rules follow it. Do not assume your existing rail meets it, and do not assume a replacement rail is exempt. Before the roofer pulls materials, call the city building desk and ask whether replacing the railing or the deck membrane needs a permit, and whether the inspection will look at the guard height. The answer changes the schedule, and it changes whether the rail gets rebuilt to the current rule.
Town roofing in Ladue
Ladue lots are large, and many of the houses have multiple roof planes, a hip over the main block, and features that sit above the rest of the roof. A widow's walk on one of these houses is often the highest walking surface on the property, and access to it is often the hardest part of the job. The crew may need to bring materials up through a window, over a porch roof, or by hoist. Those access decisions show up in the quote as hoist, scaffold or hand-carry lines, and they belong in the walk line, not hidden in the shingle price.
Because the walk sits above the finished roof, it is also the place where the water from the rest of the house gathers before it reaches the gutters. A drain that clogs during a storm can back water across the deck and under the rail. The roofer should look at the drain, the scupper outlet and the gutter or downspout that receives the overflow, and the proposal should say what gets cleaned or replaced there.
What it costs
A walk is priced by its parts, not by a single figure for the top of the house. The lines that move the number are the deck area, the membrane type, the number of posts and balusters that have to be removed and reset, the number of drains and scuppers, the flashing at each penetration, access and hoisting, and the railing material itself if it is being replaced. A quote that gives one number for the walk without these lines is hard to compare against another quote, and it is hard to tell later whether a change order is fair.
Ask each roofer to price the posts as a unit, so you can see what happens if the count changes on the day the crew reaches the deck. Ask whether the railing is being reset or replaced, and if it is being replaced, what the material is and who supplies it. Ask whether the price includes the flashing at each post or whether that is an extra. These questions take a few minutes to answer and they keep the number from moving after the tear-off has started.
What to ask
- How many posts or balusters pass through the deck, and does the proposal list each one or give a single allowance?
- How is each post penetration flashed, and does the flashing tie into the membrane or sit on top of it?
- What membrane is on the deck, and what is the warranty on the membrane itself as a separate item from the shingles elsewhere on the house?
- How many drains or scuppers does the deck have, and what is being done to clear or replace each one?
- Is the railing being reset or replaced, and does the connection go into new blocking or the existing framing?
- What guard height does the railing meet, and does the job need a permit or inspection for the rail?
- How does the crew reach the walk, and is hoisting or scaffold included in the walk line?
- Where will planters, furniture and foot traffic be kept off the membrane, and who explains that to you before the job starts?
If the answers come back vague, ask for the proposal in writing with the post count and the drain count on it. The office at (314) 220-2333 can take that question, and a written walk line is easier to compare than a verbal promise made at the door.