will hardwood flooring reinforce mildly saggy subfloor joints?

amakarevic

i have a couple of spots on my new subfloor where i can feel very mild sagging when i step on a joint over a joist. maybe 1/8" max. i was wondering if i can expect the upcoming hardwood flooring to reinforce that to the point of not being an issue or perhaps do the opposite, i.e. break the hardwood strips.

the ceiling underneath is not set so i could (with some degree of difficulty) reach the spots and set sisters (the house is 100 yrs old, hence a few saggy joists) but i'd rather not do it if hardwood is gonna do the job.

thoughts, ideas?

thanks

Evstarr

Eventually the new floor will follow the lay of the old.

joecaption

New floor will also sag, gaps will open up, and more then likly it will soon squeck.

amakarevic

luckily, i only have really 2 spots like that ... surprising that the old joists haven't sagged more but they really haven't. because they are real 2x10s when 2x meant 2 and not 1.5. i can imagine what the modern lumber will look like in 100 yrs...

100 yrs ago, money used to mean something and houses were built properly with proper material... i didn't live then but i miss it

woodworkbykirk

houses 100 years ago werent built any better than they are today. the material wasnt dressed down to a uniform size like it is today which is why back in the day plaster was used to create a flat surfce. today we use drywall panels. a very skilled carpenter can build a far superior structured house with so-so material than a diy hack using the best of materials

as for your floor issue, fix the subfloor, up the thickness or install blocking underneath before the flooring goes down. its simple common sense

RhodesHardwood

I would just replace the areas of concern with new plywood.