Last spring I caulked and insulated the part of my basement above ground, sheet rocked it, and caulked all of the seams. I ‘I am running my dehumidifier on low almost abount 16/24 hours 7 days a week. I am setting up a Woodworking shop. The construction of the walls below the 1 studded section above ground is cinder block, and it has been sealed with a Dry Lok paint. 1/3 of the rim joist on the last wall has yet to be sealed because of all the wiring, but I am getting to it as quickly as I can. The other day on the floor was a damp spot at the wall-floor joint. Last, and maybe a stupid question, should I be covering up the tops of the cinderblockd that are nott sealed? Is that my humidity maker? Westchester/Putnam border I had a new roof put on in June, and there is a downspout directing the water away from the area on the other side of where the damp spot is located. What can I get something to seal those wall joins and block the water from entering my nasement in this situation? I also need to end the humidity. Thank you for your help.

That's the thing with concrete block.
Unless the voids are filled, they're basically great cavities for this sort of thing.
Also, if you have developed cracks in the outer facing, you could be getting leakage in which is filling the cavities.

I filled the cracks with their concrete plug product and painted over those plug-ups with Dry Lok and their has been no leaks from those spots.

So I should put rigid insulation over the tops of blocks that have openings as that will make a difference?

My new humidifier is keeping my basement at 40%, but I’m not enjoying paid to run it all day every day.

Posted By CTwith3 on 10 Oct 2018 02:59 PM
I filled the cracks with their concrete plug product and painted over those plug-ups with Dry Lok and their has been no leaks from those spots.

So I should put rigid insulation over the tops of blocks that have openings as that will make a difference?

My new humidifier is keeping my basement at 40%, but I’m not enjoying paid to run it all day every day.

There's no good reason to keep the basement at 40% RH. Holding the line at 60% is sufficient for keeping mold and "musty basement" smells under control. The biggest source of moisture in most basements in summer in CT is air-leakage from the outdoors, not ground moisture coming through the foundation. When outdoor dew points are 65-70F the moisture in the outdoor air gets taken up by the slab and items near the floor that are below that temperature as adsorbed moisture. A cardboard box resting on a 55-60F slab is very likely to grow mold.

It's customary to air-seal and insulate the top of the foundation, so if there's a ledge with the open (or even closed-up) cores of the CMU peeking at you, that's both an air & moisture leak. Ideally there would be a good capillary break between the foundation and moisture-susceptible foundation sill such as metal flashing or an EPDM sill gasket. CMU and poured concrete wick moisture fairly strongly. If the foundation is wet, sealing it up completely with an impermeable foam board it could raise the moisture content of the foundation sill & band joist to troublesome levels. Buy a 2-pronged wood moisture meter and measure it. If it's 20% moisture content or higher it's time to consider jacking up the house a hair and slipping some EPDM under the foundation sill. If it's under 10% go ahead and install foam board on the top of the ledge.

Its 40% because I also use my basement as my woodworking shop.
I rdered a moisture detctor and should receive over the weekend. Once received I will check my cinder block walls.

Keeping it at 50% is almost always fine for wood. Letting it stray north of 65% isn't, but with a sealed tight basement you should be able to maintain 40% without breaking the bank if the ventilation rates are kept under control. Right now in Hartford the outdoor dew point is about 43F, which corresponds to 41%RH @ 68F, so infiltration/ventilation right this minute isn't going to add significant load to the dehumidifer.

But for most of the summer the outdoor dewpoints are in the mid-60s. A dew point of 65F in a 72F basement corresponds to a relative humidity of 78%RH, and is a VERY significant load if holding the line at 40%RH , still significant (but less) if only holding the line at 50%RH.

The air tightness of the basement to the outdoors really matters more than mere vapor tightness at the foundation wall or floor. The latter is real enough, but still a secondary issue in your climate.