PROPERLY FINISHING WOOD FOR MANTEL
Tips on how to seal and stain a piece of lumber to match with your interior fireplace
Q How should I finish a thick piece of elm wood we want to add to an existing fireplace mantel? It came from a tree cut from our property and sawed into lumber.
A Wood three or four inches thick can take a long time to dry. How long has it been since the log was milled? The only effective way to ensure sufficient dryness for finishing is by storing your wood in a fully heated space, perhaps for a year. As for finishing, you should start by sanding your wood to the same level of smoothness as the wood of your mantel. Apply interior wood stain, followed by a sealing coat to protect the wood against dirt. That said, there's a danger. You never really know how a stained and sealed wood surface will look until the stain and all coats of sealer are applied. ideally, you'd want to complete the finishing process on a scrap piece of the elm you intend to use. Only then would you go ahead and finish the piece you want to install. This is more work, but it ensures you won't have any unpleasant visual surprises. Urethane is a great option for sealing in your situation, and I recommend a product with a satin sheen. This has almost no gloss and hides imperfections better than a gloss urethane. Most urethanes are water-based these days, and since this type dries so quickly, it often leaves behind bubbles and brush strokes. One of the few non-water-based urethanes out there now is Varathane Pro Finisher. This is a solvent-based urethane that makes it easy to get great results. If you've had trouble with urethane before, you won't with this stuff. Apply one coat, let it dry completely, then sand very lightly with 220grit sandpaper, either by hand or with a 1/4-sheet finishing sander. This is a key step. Vacuum all dust off the surface, then apply one more coat with no sanding afterwards.
Q We've been told that we have mould in our attic. What are your thoughts on dealing with this, and how can we find a reputable company to clean things up?
A Sometimes lumber in attics can have dark stains from mould that grew on the wood when it was piled up, and this type of mould is of no consequence.
But in your case, what does the mould look like? Who told you about it, and what did they see? The reason I ask is because professional mould abatement can be very expensive, and perhaps it's not necessary in your case. Mould almost always grows because sufficient moisture is present on some food source like wood. No moisture means no mould. Have you had a leak in your roof that may be feeding the mould? Sometimes condensation can build up in attics and trigger mould-promoting condensation in winter. If the mould is localized to an area up to a couple of sheets of plywood in size, then you can deal with it yourself
(or have a handyman deal with it). After stopping the source of moisture, treat the area with a registered fungicide. The best I know is called Concrobium. It's an odourless, nontoxic liquid that you spray on mouldy areas. It works by mechanically crushing the mould spores as it dries, so it does not rely on any compounds toxic to people or pets. Not only does Concrobium kill mould, but it helps prevent mould growth. If you have a massive mould issue in the attic, then a professional will be required, but only after the source of moisture is eliminated. You'll probably need some kind of building professional for the moisture side of things, or a heating ventilation and air conditioning expert.