I have almost a 2 inch gap between my wooden floor and wall in the apartment I am renting. I think the dust down there is causing me allergies and I’m worried about the cold AC air escaping down there. Is there a REALLY quick easy way that I can fix it that my landlord is likely to approve? The hole down there is about 10 inches - it is through the floor not just the hardwood planks.
The floorboard are on top of old floorboards that do not line up and neither reach the wall. The coin is a 5 cent coin. Thanks again!
Without seeing it, my first inclination is to get some extruded foam board (not beadboard/Styrofoam--it's too messy) of suitable thickness (3/4" for just the depth of the hardwood, 1" or 1-1/2" for hardwood plus subfloor). Using a utility knife and a straightedge, cut strips that will fit snugly in the gap. Press them in by setting the inner edge against the floor and tilting the wall side down.
If you fit them well they'll be self-supporting and make a great seal. That said, this probably isn't the only air access to the floor framing. If there's significant air movement between floors you may not solve the problem with this patch.
This is what "baseboard" is for. If you are renting, your landlord should be amenable to installing baseboards for you, they are a standard way of taking care of that gap between a wall and floor that always exists.
If you end up having to do it yourself, you can buy vinyl (rubber) baseboard strips (also called "wall cove base") that are over 2" high and come with peel-and-stick adhesive on the back. Very simple to install and can be cut to length with basic heavy duty scissors (like "kitchen shears" or cut with a razor knife.