Roofing in Centralia
Centralia is an older town in the north of Boone County with a manufacturing history and a housing stock to match. A large share of it predates the war, the streets are laid out on a grid, and the trees planted when those streets were new are now very large. Roofing here has more in common with central Columbia than with the subdivisions to the south.
Masonry chimneys are everywhere, and they are the main event. Houses of this age were built with real chimneys, often more than one, and every chimney is a hole through the roof that has to be flashed. The correct detail is step flashing, small interleaved pieces stepped up the slope with counterflashing let into the brickwork above. Three things go wrong with it. It was replaced at some point with a continuous strip of metal and a lot of sealant, which is a repair with a timer on it. It was reused when the roof was last done, so new shingles sit on forty year old metal. Or the leak is not the flashing at all, and water is entering through a weathered crown or failed mortar in the stack itself.
That third case is worth labouring, because it explains a lot of repeat leaks. Water in the masonry appears inside the house in exactly the same place as a flashing leak, and no amount of roofing fixes it. A roofer who tells you the chimney needs tuckpointing before the roof work is worth taking seriously rather than treating as a brush off.
Shade changes the maths. The canopy over the older grid means many roofs, particularly north slopes, stay damp for hours after the rest of the town has dried. That grows algae, which is mostly cosmetic, and it packs valleys with leaf litter, which is not. A valley that is holding a wet mat of leaves is pushing water sideways under the shingle courses. Open metal valleys are the sensible specification here, and clearing them twice a year does more good than any product.
The framing is different. Older Centralia roofs are commonly steeper than the post war ranches further south, which is good for shedding water and more expensive to work on. Steep roofs need staging and proper fall protection, and that shows in a quote legitimately.
What is underneath. Plank decking with gaps between boards rather than modern sheathing is common on the oldest housing. That is not a fault, but a modern shingle wants a solid deck, so sheeting over it is often part of the job and needs to be in the quote rather than discovered.
Permits. The town runs its own utilities, which people sometimes assume means it runs building permits too. Establish with your roofing company which office they are filing with.
One independent mid Missouri roofing company receives requests from this site. Leaks and flashing covers the chimney question in more detail, and Hallsville covers the country to the south of here.
Questions people ask
- Why does the roofer keep talking about my chimney?
Because on housing of this age the chimney is the single likeliest place for water to get in, and there are two separate problems that look identical from inside. One is the step flashing where brick meets shingle. The other is the masonry itself, where a weathered crown or spalled brick lets water into the stack. Flashing work does nothing for the second, so it is worth establishing which you have before paying for either.
- The north side of my roof is green. Is that a problem?
It is algae, and under heavy shade in a humid climate it is close to inevitable. On its own it is cosmetic rather than structural. What matters is whether it is holding moisture against a covering that is already at the end of its life, and whether the shade is also filling your valleys with leaf litter, which genuinely does cause damage.