Floor in houseboat

[Bdunbar44]

test drill your stringers and transom. use a 5/16" drill, mark off 3/4" length. drill into the encapsulated wood of the stringers and the transom about 4" up from the bottom of the deck. if the wood shavings come out dry, light colored, and smell like fresh sawn wood, then you are good.

however if the shavings come out wet, dark and smelling of rotten mulch, then the structure of your boat is gone.

literally the last thing to rot on a fiberglass boat is the floor.

we are saying this to help you understand exactly how dangerous a boat is with soft spots in the floor, especially a houseboat

at a minimum, read thru link #14 in the hull restoration sticky. https://forums.iboats.com/threads/how-tos-and-other-great-information.283508/

I’ve checked and the structure is hard and dry. I feel like the sponginess is coming from laminated flooring he put down and he used 1/2 plywood underneath. The boat doesn’t have any water in it. Maybe some oil under the engine but that’s it. I feel like the 1/2 plywood is to thin and I’m a bigger guy. Ive only owned the boat for 3 months and I’ve done a ton of upgrades. Not like I’m a cheap skate or anything but I’m getting to where I wanna enjoy the boat instead of working on it constantly. I got the engines going and the impellers changed out on the engine and generator. I feel like the soft spots are coming from the 1/2 plywood when it probably should have been at least 3/4

 

[topgun3690]

 

[Bdunbar44]

Wow a video of a houseboat sinking! 🫣 Can you send a video of one floating? Never seen that before?!

 

[airshot]

Please bare in mind that myself and many others on here have been around boats for over 60 years. I have watched more rotted boats come apart and sink than I have fingers and toes to count on. A few of them included fatalities. We don't want to see more of this happen ! Why we may sound harsh, we don't want to see folks get hurt or completely turned off to boating because they found themselves in way over their heads with major repairs. Sounds like you plan on moving forward, so be careful and make safety your first priority ! I would like to see some pics if you have any, good luck on your project.

 

[Bdunbar44]

Please bear in mind that myself and many others on here have been around boats for over 60 years. I have watched more rotted boats come apart and sink than I have fingers and toes to count on. A few of them included fatalities. We don't want to see more of this happen ! Why we may sound harsh, we don't want to see folks get hurt or completely turned off to boating because they found themselves in way over their heads with major repairs. Sounds like you plan on moving forward, so be careful and make safety your first priority ! I would like to see some pics if you have any, good luck on your

 

[Bdunbar44]

Thank you sir

 

[Scott Danforth]

post pictures of the underside of the deck, the transom area from around the motor, the stringer grid.

1/2" floor should be more than adequate with a sound stringer system. I believe they are on 16" centers on the early 70's gibsons....unless the floor has had an improper repair/replacement in the past which is entirely possible, or the stringers are rotten. the floor of my boat is 1/2" of foam core with about 0.060" of fiberglass on both sides. you can have 6 drunk people dancing on it and it wont flex.

you are not the first gibson house boat owner to come here and start a restoration thread about soft floors. one guy started gutting his boat while floating wanting to move a wall, and the rotten stringers collapsed, turning his V-hull to an inverted V-hull.

 

[Bdunbar44]

post pictures of the underside of the deck, the transom area from around the motor, the stringer grid.

1/2" floor should be more than adequate with a sound stringer system. I believe they are on 16" centers on the early 70's gibsons....unless the floor has had an improper repair/replacement in the past which is entirely possible, or the stringers are rotten. the floor of my boat is 1/2" of foam core with about 0.060" of fiberglass on both sides. you can have 6 drunk people dancing on it and it wont flex.

you are not the first gibson house boat owner to come here and start a restoration thread about soft floors. one guy started gutting his boat while floating wanting to move a wall, and the rotten stringers collapsed, turning his V-hull to an inverted V-hull.

I’m actually pulling the boat in the spring to have the lower unit serviced and the baffles replaced. While it’s out I will paint the bottom and look at the floor issue a little further. The spot is under the back glass door so I’m thinking some leaking issues with that door has caused this. Everywhere else is solid. My goal till spring is to fill the yeti with brew and enjoy it. After reading everyone’s most extreme what could happen I’m just gonna make sure of what I already know and that is it’s a solid boat except for the spot under the door and I’ve built 2 houses so I’m pretty sure I can fix it to what I think is sufficient. If it sinks (which it won’t) I will use the yeti for a float and swim back and buy another boat! Although I love the boat I should have listened to my late grandfather who also had a houseboat when he said there nothing but a floating money pit. Lol

 

[Scott Danforth]

a boat is a hole in the water you pour money into.

 

[flashback]

If you don't do anything else at least remove the the old flooring.

 

[racerone]

Just go to the local lumber yard.----Get some 3/4" marine plywood.----Install it and don't worry about it again.