Is this water damage?

Question

https://imgur.com/3FO7gpk

I have been living in my house for about 5 years now. This is the baseboard in the basement. This just showed up this year, never had anything like this in the previous years. We have had some down pour rain in the area and since this is a 1940s house, I assume that it's not waterproofed correctly for downpours.

The rest of the baseboard in the basement is completely fine. This area also happens to be right below an egress window for the bedroom.

EDIT: Dug up the gravel in the egress window and found this crack in the foundation which lines up with where the water damage is https://imgur.com/ZSvr9mv

Answer 1

The best bang for your buck with water penetration is not doing a root cause for the specific entry point, but ensuring that your standard water prevention is up to the highest degree, then re-evaluate your priorities. Obviously you need to fix the damaged spot but given it might happen again, that's less important.

Cracks in the foundation may let water in at a slightly higher rate, but gallons gallons of invisible water enter poured concrete basements every day in the form of humidity and hydrostatic pressure. Hydrostatic pressure can cause visibly settling water to seep out of the concrete as if pressing down on a wet sponge.

The old basement technology was brilliant. The basement served as a reservoir for this humidity, and then it eventually passed through the wood floors or it settled into the concrete and left the way it came once the surrounding soil dried out. This was never intended to be a living space.

It simply may not be possible to have a finished basement in the house you're living in. It factors depending on the type of soil your house is built upon, the slope of the landscaping around it, and the type of climate you have. If you have a budget for it, you can do some simple and complex remediations:

• Just keep a humidity monitor and check your data to know the times of year and exposures that increase humidity in your house
• Check your gutters, extend your downspouts ALL the way out there.
• Extend your rafters and eaves
• You can buff up your egress by installing a shield which is allowed by (my) code as long as its operable and you can actually get out in case of a fire.
• Grade the soil around your foundation to shed water away from the house
• Dig trenches where applicable to divert water
• Move plants and watering away from the foundation
• Keep a dehumidifier running in the basement
• Install a sump pump in/around the low point of the basement as some insurance in case of a flood (usually, this is when the sewer backs up through a basement drain.)

Answer 2

It certainly looks like water damage.

Now you get the joyous task of trying to determine where the water got in. Which, with an already finished basement, is a pain in the arse.

Or you can consider cutting out the damaged section, cutting the wallboard back to an inch or two above the floor, and installing pressure-treated 1x2 boards as your baseboards. That won't do anything to keep water out, but it will keep small amounts of water from getting wicked up into the plaster, and will give you a rot-resistant area in contact with the floor.

There are other answers about how to keep water from entering in the first place, which may be expensive given where you're starting from, or how to try to catch it before it does damage (perimeter drains and the like). Searching for "basement water" should find most of them.