Hump in House Boat Floor

[growing pains]

What would cause a hump in the floor of a fiberglass houseboat? The stringers are solid and in excellent condition. I noticed a slight hump in the floor after lunching but by the end of the season I couldn't open the locker door without it scraping the floor. Now that boat is dry docked for the winter the hump is gone.

 

[WIMUSKY]

Bump for Topic move.........

 

[DeepBlue2010]

Did you take pictures when it was there? Seems to be moisture accumulating in the deck. How do you know the stringers are solid, what did you do to test them?

 

[fhhuber]

What would cause a hump in the floor of a fiberglass houseboat? The stringers are solid and in excellent condition. I noticed a slight hump in the floor after lunching but by the end of the season I couldn't open the locker door without it scraping the floor. Now that boat is dry docked for the winter the hump is gone.

Sounds like something is wrong under the floor there...
either structurally with hull flexing and forcing that bit of floor up or something is swelling with moisture.

The question becomes what is the mode of the floor flexing... Is the force of water on the hull pushing the sides of the boat together and warping the floor? (then when the hull is on blocks/trailer you have the sides spread from each other, and bye bye hump)

How long did it take for the hump to go away when you got the boat out of the water? If it was rapid then its the hull flexing.

 

[alldodge]

What would cause a hump in the floor of a fiberglass houseboat? The stringers are solid and in excellent condition. I noticed a slight hump in the floor after lunching but by the end of the season I couldn't open the locker door without it scraping the floor. Now that boat is dry docked for the winter the hump is gone.

Howdy

My guess is your stringers and cross members are not in good shape, they only appear to be. When the boat sits in the water the weight is distributed evenly across the hull, the week spots are flexing more then they should. When the boat is put on blocks the center keel in most cases is now taking most of the load. Being the keel the sides of the boat are stretched further out and the bow goes away.

Suggest getting into the hull and drill small pilot holes and check for moisture in the wood

 

[mxcobra]

swelling plywood do to moisture and heat under deck

 

[gm280]

So many great suggestions and ideas already posted. Post some pictures of the suspect area for everybody to see. But it isn't likely to fix itself. JMHO!

 

[Woodonglass]

OH NO, could it be the RARE and DREADED Boat Stringer Mumps?? Did you have your boat Immunized??? You know Fiberglass Boats get the measles too!!!! You can't be too careful when it come to boat health. Always have to be on the lookout for these dreaded diseases. All the "Boat Doctors" here on the forum will be able to diagnose and prescribe the correct "Medicine" for her but it does take precise descriptions and lots of pictures.