My tent

I have a tent and it is great. It's does well in inclimate weather and doesn't allow for any build up of condensation on the fly in the mornings (not yet anyway.) I just want to know what you all think about sealing the seams, and possibly adding a coat of Nikwax, or something else to help ensure the waterproof/resistant-ness. The company says that it is "made of high quality materials" and that such is unnecessary and mabye even frowned upon. What do you all think?

yes, seal the seams. Go to your local sporting goods store that sells tents and buy a tube of water based seam sealer. Almost everybody sells the Coghlan's brand.

If the walls on your tent aren't leaking - leave 'em alone. I've seen a few people pull their tents out of a stuff sack with the tent glued together in a ball.

that spray stuff for material often remains tacky forever.

It is hard to answer your question without some details of the materials of which the tent is made. For example, old-school canvas tents (cotton or cotton blends) are actually quite waterproof because the fibers absorb water and expand, sealing the tent quite well. There are products specifically made to aid in the process, referred to as waterproofing for canvas tents. Seam sealing does no good on these, since the expansion of the stitching when wet does all the seam sealing you would want. But there are some problems - the tents develop a smell after a while, especially when treated with the waterproofing chemicals, they weigh a lot, and they will mildew unless well cared for.

Nylon and polyester tents are made either as single wall or a main tent plus fly. If single wall, the tent body is a "waterproof breathable" material that is a laminate similar to Goretex. That is, a nylon or polyester main cloth to which is laminated a PTFE (like teflon) or other plastic (often polyurethane) that is microporous. Some of the materials, like Toddtex (Bibler) or Tegraltex (Integral Designs), also have a fuzzy wicking layer on the inside that helps wick the moisture through the microporous layer. These require seam sealing. Many are taped, but a good seam seal as a supplement is insurance, especially after years of hard use.

The tents with flies have a very breathable main tent body with a fly that is nylon or polyester that has a flash coating of a plastic, usually polyurethane. The seams on the fly may or may not be taped, but again seam sealing is needed.

Some tents (mostly tarp tents, like Black Diamond's Megamid), usually ones without a floor, are more like a rain fly in that they are a coated material that is not breathable. These, like a fly, need seam sealing, especially after much use (periodic resealing, too). There are some floored tents that are completely waterproof, but they obviously need a lot of ventilation (otherwise you can't breathe for very long).

In most tents with floors, the floor is a heavier material that is flash coated. Some floors are of a "bathtub" design that has no or only one seam on the floor, with the floor being folded up along the tent walls. The seams on the floor and where it joins the tent wall must be seam sealed, even if taped, again as in all cases of sealing, re-sealed periodically.

Condensation - in certain conditions, I have never had any condensation. Specifically, in my desert camping and at altitude in dry climates (summer in the Sierra, Rockies, etc). In other conditions, I have gotten condensation in every tent I have ever had or used, single or double wall, no matter the material (including the military canvas tents we had at the National Jamboree each time I have been on staff). The condensation can be kept to a minimum by ventilation and air flow. But if the temperature and humidity conditions are right (or wrong, depending on your viewpoint), you are almost guaranteed of condensation (in my house in Mississippi, we got condensation on the walls in summer unless we ran the air conditioner/dehumidifier full time! Same in the basement of our house in Boston.). Winter camping often involves condensation (which can be frost on the tent walls). Yes, there are ways to minimize it, but you will find the perfect conditions for it sooner or later if you camp in enough different seasons and locations. Obviously, the best prevention is to just not camp in those conditions - for example, avoid rain forests and late spring blizzards where the temperature is right at the freezing point.

Slight disagreement with Ed on the NikWax - NikWax is a company that makes a wide variety of products, including a very high quality seam sealer. They also make waterproofing products for a variety of materials, and they make DWR and cleaning products for a variety of materials. None of the waterproofing products are for tents or flies. They are for boots, gloves, and such. If you have a single-wall tent made with a waterproof breathable material, an occasional washing with a product made for wpb (NikWax and McNett make these) and retreatment of the DWR (durable water-resistant) helps. The DWR helps the water bead up and avoid wpb (like Goretex) "wetting out".

However, more generally, Ed's comment about using NikWax can be extended - if you are referring to the rainfly, it's already flashcoated with a plastic (probably polyurethane). Aside from the needed seam sealing, there is NO product that can make the coated nylon or polyester more waterproof. You should clean and thoroughly air dry the fly to extend the life (keep the coating from delaminating), and of course, thoroughly dry it after it gets wet from rain or snow. Maybe I should say "postpone the delaminating" - coated materials will eventually delaminate and/or crack. Proper care will give you years of life.