My only guess is that it is a floor board of somesort that has somehow pushed its way up which is pushing up the carpet about 1 2 an inch in a 4 foot strait line.
Lumps under carpet padding.
The bumps may appear when the carpet padding wears down enough to create slack in.
If you can feel a soft spot in the floor under the carpet the subfloor has likely been weakened or damaged.
Rebond padding is made up of chunks of recycled foam material that s bonded together into a big sheet.
Is the bunching in the high traffic areas like doorways and halls if yes carpet is not stretched enough.
I recently had a client with a home in contract that had little bumps under the carpet in several different spots in the living and dining room which was about 15x30 feet in size.
This isn t the same as having a floor squeak when you step on it which simply indicates that the subfloor isn t tightly fastened to the floor joist in one area.
Over time your carpet can develop lumps bumps and wrinkles that are unattractive and potential tripping hazards.
Good neighbor is right time to replace the carpet.
Instead a dip in the carpet could mean that a floor joist has sustained.
I had new carpet installed about 6 months ago and just last night i noticed a fairly large about 4 foot long lump under my carpet and it was not there last week.
Carpet padding is typically sold in rolls containing 270 square feet of padding.
If the carpet moves the pad can move if it wasn t stapled properly causing bunps in the pad and carpet.
These are the rock like bumps i was feeling under the carpet.
You may not beleive this but the hard bumps are the carpet padding.
Not only are lumps unattractive and cause eye sores but they are a hazard that causes trips and falls.
Typically carpet is attached to floors by tackless strips or double sided tape.
No under pad should have lumps in it call for a concillation anyway.
At one big box home retailer recent prices for a roll of carpet padding ranged from 50 19 per square foot for a recycled foam padding with a density of 5 to about 300 1 11 per square foot for a top quality memory foam padding with a density of 10.
Unfortunately because of its composition some of the recycled chunks are very hard and dense compared to the rest of the chunks.
The pad is made up of various foam peices and youa re feeling the hard peices as the rest of the pad compresses.
Since the buyer was an engineer he decided to investigate the situation himself rather than call an inspector.