Up, up and not away!

Depends. The range in specific gravity (density) for Doug fir in a large sampling in the West was .33-.59. 95% of all samples were between .36-.54 with the mean being .45. This sampling was done in the late 60's and early 70's and included old growth trees. Studies have shown that Doug fir from low elevations can have wood 10% denser than from higher elevations in the same region. In addition, Doug fir from west of the Cascades and from low elevations in the Inland Empire can be up to 20% harder than Doug fir sourced from the Rocky Mtn. region (Colorado/New Mexico). Younger trees do have lower average specific gravity (density), but this is mainly due to the effect of juvenile wood in the inner core of the tree (10-20 years). The center of the tree is not typically used for making select or clear flooring because of the large number of knots. Additionally, studies with Doug fir have shown that once the tree reaches about 75 years, the specific gravity levels off around .50 and only trees from low elevations in the Cascades showed an additional 10-15% density increase into the "old growth" years. Wood doesn't harden with age. Once it is kiln dried to 6-10% MC (and the pitch is set for Doug fir) it has a given specific gravity. The only way that would change is to add something to it like water or chemicals. High ring count (in a given piece of wood) could be caused by a young tree being suppressed or by an older tree with slow growth due to old age. Generally, once a tree reaches 50-75 years in age, the specific gravity of the wood from that point out does not change much. Janka hardness is directly related to wood density or specific gravity. Lots of grain (like in rift-sawn, tight ringed Doug fir) tends to mask or hide dents. A satin or matte finish also tends to hide surface scratches. Doug fir is fine for flooring, just accept that it will dent more.

Are you sure the "Water Seal" you refer to is an oil based (requiring a petrochemical to clean the brushes and NOT soap and water)? Is it "transparent" and has no color listed or shown on the can? There is no need to "strip" or "sand" the Thompson's Oil based TRANSPARENT Water seal Product because the paraffin soaks into the wood and is not on the surface. It has no pigments in it that rest on top of the wood. Therefore there should be no "peeling" or "chipping" of the surface and no obvious wear other than wear to the wood itself, usually near stairs and door and very slight in most instances. If its the Thompson Oil Based Transparent product you used, there is no need to strip or sand. You may want to clean the surface (IF it is visibly in need of it) with something like diluted Clorox Exterior house cleaner to remove pollen, dust, dirt and any surface mildew (mildew spores are transported by the wind and there is always some on the surface, although it probably hasn't "stuck" to it. Its basically a spray or brush on job and rinse with a garden hose. Let it dry fully for at least a day (two is better). then you can apply your new oil based deck product. I suggest you wait at least one full year for the beading of water to stop and even two years is OK. My front deck got the Thompson's two years ago and I will stain it with an oil based stain this year. It requires minimal cleaning....I may just use a garden hose with a firemen's nozzle. The deck gets full sun all morning so mildew is very hard pressed to survive there. Best stain, IMO are oil based TWP. The main thing to watch for is to avoid "soap and water cleanup" because that is a water based, possibly latex deck product. You wouldn't think to put latex paint on your indoor hardwood. Latex wears like crap to foot traffic. A true stain soaks the color deep into the wood and is not a "paint pigment" that sits on top of the wood. The whole problem with deck preservation has been caused by the VOC controversy which tossed a lot of good products out of the market by legislation. The emphasis on water based products opened the door for a lot of "new" water products with "paint stains" which are not stains at all. Unfortunately, those products require stripping because they wear out fast, leaving some areas bare and have adhesion problems as they age. Stripping is more work than the refinishing. ALWAYS google the Material Safety Data Sheet of the product you are considering so you know exactly what it is. Be careful that most big box stores sales clerks are "selling" what the store has in stock. That is why they get paid. The best products used by Contractors are available through building supply vendors that cater to builders and carpenters and not the general public consumer. They do not refuse to sell to the general public, but "quality" is their life blood, not quantity of sales based on huge purchasing contracts supplying a nationwide chain. Wish you good luck. Don't be swayed by the claims of 6 year and 10 year lifespans. If its a water based paint pigment product, it will look like hell for half of those claimed "lifespans", Most people would prefer a true stain that can be reapplied easily without having to strip the deck. And. if you have to strip the deck, how do you strip the railings and balusters? I've done it....took a pressure washer and two days to complete. Then I started reading and wised up on the number of really crummy products that are available, being pushed by big box stores and consumer agencies that prioritize water based over oil because of an "environmental" bias. The idea behind using an initial Thompson's Oil Based Transparent on a new deck comes from a highly ethical, lifelong contractor/carpenter who needed a workable solution for customers who couldn't decide how they wanted there decks treated during an age of great confusion. The Thompson Transparent has an effective anti-fungal and gives good service up to two years. When you compare to other oil based products costing three times as much, many of them also recommend restaining after two years. BTW, oil based paraffin products do not support fungus.

Yes there has always been a fair amount of pitch but last year was amazing. Icicles hanging down. This year. None. I know they damaged the root system about 5 years ago when they put in a retaining wall. Th tree still seems healthy though. It is about 80 feet high and the trunk is likely 3 feet through. Appreciate your interest I find it curious.