1890's Victorian Discoloration/Staining Roof Deck Planks

[John McGuiness]

Hi guys,
The attached pictures are from an 1890’s Victorian in Upstate NY. The attic roof deck showed severe discoloration of the wood planks in several areas with the staining being very black (almost the color of charcoal). The insulation and ventilation was minimal which would generally send me to the direction of mold. It should be noted the original slate roof was recently replaced approx. 3 years ago with architectural shingles. Could this discoloration be more indicative of moisture issues possibly associated with the older roof and rusting of nails and/or some chemical reaction in the wood from the moisture and possibly wicking of some of the slate materials (an older roofer buddy said he often sees staining from slate)? I was also informed by the selling agent that the slate roof was actually installed over an original tin roof which was problematic for the slate in terms of consistent maintenance. The attic was full with cardboard boxes which did not show any signs of mold/mildew which I would think would be the case if the problem was active from possibly warm moist entering the dwelling in the winter months and condensing on the attic ceiling. When touching the staining I would get a very faint black residue on my hands. Any thoughts would be appreciated.
Thanks,
John

[John Kogel]

There is some staining there from past roof leaks. Big deal, the roof has leaked a few times in 120 years. If the wood is sound, it is better than anything you'd buy to replace it.

Old houses have battle scars. If your clients are squeamish about stains, rat turds, wasps and spiders, asbestos, knob and tube wiring, cracked plaster, loose brick chimneys, and maybe even some patches of mould in a closet or behind the laundry sink, hey, wrong house.

[Bryce Jeffrey]

I agree with John! I live in a heritage home and specialize inspecting them.

They are an investment in the heritage of your community and they require ongoing care and financial investment. Many times what you see is what you get.

In my early days, writing a test inspection for OAHI I inspected my lawyers home. Designated heritage home in London Ontario. Attic ventilation was not to to-day's standards.

My inspection comment: "Been doing its job for 150 years. If it ain't broke, don't fix it!"

Comments from OAHI: "Unprofessional language!" LOL

[Mark Reinmiller]

Past leaks, maybe some condensation. The stains and wood darken over time. Nothing to worry about. The faint staining on your hand-probably years of dust/soot accumulation.

[Ian Page]

I'm fairly sure the staining is a pitch tar or creosote applied waterproofing over the original decking. I grew up in and around slate roofed houses and that staining, as it bled through the boards over time, was typical - especially under true Victorian era slate roofs.

[Scott Patterson]

When that home was built coal was the main heating source. Many times the flues would leak and the attic areas would fill with smoke and cinders from the coal burners in the home. Many homes would catch on fire in the attic areas, it is not unusual to see attic rebuilds and repairs on old homes. If you were able to remove some of the blacking by rubbing it with you finger, that is most likely soot from the old days of burning coal to heat the home. If the darkening was due to heat and past leaks, the black would not rub off.

Yes, it could also be related to the old slate roof. It is a non-issue as long as the wood was sound and you didn't find any leaks...

[Raymond Wand]

That attic is in need of upgrades, poor insulation, bad ventilation, air leakage from room below into attic, exhaust duct does not appear to be vented to exterior, nor insulated.