How to straighten my boathouse?

[check]

OK, platform for scaffolding is built. Just need to put on one more row of plywood. Then I can climb up and check out all the roofing boards and roof rafters and what not to make sure none of them are soft.

I lightened it up for you so the scaffolding can be seen.

View attachment 607668

Thanks, Jaylegger!

 

[PILOON]

One sure has to admire your determination.
Just be careful.
Mind U I understand meeting challenges and the satisfaction of winning.

 

[Jaylegger]

Thanks, Jaylegger!

Looks like you might intend to keep the new floor structure and increase the boat house functions.

 

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Looks like you might intend to keep the new floor structure and increase the boat house functions.

Yes, it does look kind of cool, doesn’t it? But I need all that lumber elsewhere after the new roof is on.

 

[Jaylegger]

Yes, it does look kind of cool, doesn稚 it? But I need all that lumber elsewhere after the new roof is on.

That would be really nice. You could ramp down to a floating dock, add a few windows, turn the interior into more of a storage/habitable space, while still having room underneath to float in smaller boat to get them out of the elements.

 

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That would be really nice. You could ramp down to a floating dock, add a few windows, turn the interior into more of a storage/habitable space, while still having room underneath to float in smaller boat to get them out of the elements.

Very creative, Jay. You know, with 13 ft. wall studs, I could have a mezzanine level!

 

[check]

Very creative, Jay. You know, with 13 ft. wall studs, I could have a mezzanine level!

As long as I have room underneath for my Pontoon boat with the ski bar. (It is a bit tall.)

 

[check]

OK, platform is ready, scaffolding is up, and I climbed up and checked out the roof super structure. All sound, but the roof boards are leaking pretty badly on the East side (LHS in the photo). You can see how the deck is pretty much soaked over its entire 32 ft. length.

I am going to just straighten the walls where they are, and then make the whole thing rigid with a series of crossers and move the whole lake-end of the boathouse as a unit. That way the walls cannot go out of vertical anymore.

Meanwhile, the roofers are suggesting to sheet over top of the old boards with 7/16” OSB before applying new shingles (but AFTER taking off the old ones, of course). This would only be done on the East slope since that is where the leaking is. I had not thought of that, since my idea was to REPLACE any bad roof boards.

One issue: trapped moisture between the old roof boards and the new plywood? Keeping in mind that the underside of the old boards are exposed and thus able to dry out.

I am also thinking I should ask them to use 1/2” Spruce plywood instead of 7/16” OSB.

Thoughts?

 

[MossRoad]

As I recall, laying one roof deck over another roof deck has to be thought out as to if the walls can bear the additional load. If the walls are up to it then OK. Plywood is pretty rigid and will add a lot of integrity to the roof structure. If they get all the fasteners through the plywood, then through the old roof wood, then deep into the rafters. If they just punch them through the old wood and don't hit the rafters, then you're at the mercy of the original fasteners to hold the entire roof on and in square plus supporting the additional weight of the new plywood and shingles. At the least, I'd have them replace any rotten old roof boards first, and show you what fasteners they're planning to use.

As for moisture between the layers of wood, I wouldn't be that concerned. If you have good cover over it, and it's open-air under it, it's gonna stay pretty dry, I'd think.

 

[PILOON]

For my 2 cents I prefer plywood over ASB for the small difference.
OK, structurally both are good but exposed to elements? and leakage?

My take is OSB is merely sawdust glued together with a water based glue.

Shucks I've made boats with plywood but I'd never consider OSB as an alternative.

If U want real test, leave a piece of each product exposed to the elements for a month or so and let us know the results.

 

[/pine]

...Shucks I've made boats with plywood...

Lots of the famous series of 'PT' boats used by the Navy in WWII were made with (Douglas Fir marine grade) plywood...often powered by twin Allison and or Packard 12Cyl mills...!

 

[rScotty]

Too bad there are no convenient trees to attach to so that you can pull at the top. Hmm.... how about an anchor? Or hire a barge with a winch and have him anchor close by.
rScotty

 

[check]

For my 2 cents I prefer plywood over ASB for the small difference.
OK, structurally both are good but exposed to elements? and leakage?

My take is OSB is merely sawdust glued together with a water based glue.

Shucks I've made boats with plywood but I'd never consider OSB as an alternative.

If U want real test, leave a piece of each product exposed to the elements for a month or so and let us know the results.

Been there done that. The OSB turns to mush. I think the roofers’ assumption is that there will be no exposure to moisture. I don’t buy it.

 

[Cat_Driver]

I live (6 months each yr.) in a 289 year old house that I do not believe has ever been inspected.
Not in the "heartland", but the Democratic Peoples Republic of Taxachusetts.
I have lived in this house for many of my 78 years.
It sags, plus creaks and groans in high winds (hurricanes- many)
Should I be worried?
Would it be more safe if I had it "inspected" 289 years after being built?

OH well that make you absolutely safe from ever being sued, your house fallimg down, being inspected, etc. I never knew that
as long as you live in a house for 78 years your immune from all the laws of the land. Can't wait till I tell the inspector that
comes on my property because I want to LEGALLY install somthing that needs inspecting by those pesky things called
laws, that I'm immune from him poking his nose around my 78 year old house that is sitting on a 45 degree angle that
it's all good because it's been good for 78 years.

Seriously do you know how silly you sound right now.

 

[Cat_Driver]

Engineering is not tha same everywhere. Different areas have different loads that must be considered for the structure

Thanks for proving my point.

The engineering for a 2"x4" is the same math in every sate because those numbers come from the manufacturer. The math engineering on a 12" steel beam is the same all over the country because those numbers come from the manufacturer. No "engineer" can change the numbers in the products they purchase.

Different areas have different loads that must be considered for the structure. In other words
ENGINEERING is EGINEERING just because the numbers, laws, requirements change doesn't mean anyone can ignore THE NUMBERS FROM THE ENGINEERS
and to get any conclusion all 50 states use ENGINEERS to get their answers.

Engineering is a PROCESS it's not a number!



Just because ons state says a building can lean over 30 degrees and anotehr state says 45 degrees they both are still using engineering - like I said.

 

[s219]

I wouldn't use OSB. For a structure like that, I'd look into replacing individual roof boards if it was a limited area. I'd feel much better about having real solid wood up there on a roof like this, so close to water/moisture. I don't even like the idea of plywood unless it's laminated with moisture rated glue.

I built my boat house roof with treated lumber frame and metal panels (like a pole barn pretty much) because I was worried about moisture and dampness. My neighbors did plywood roof with asphalt shingles, and you can see the moisture build up under there sometimes. It's open on all four sides too.

 

[fried1765]

OH well that make you absolutely safe from ever being sued, your house fallimg down, being inspected, etc. I never knew that
as long as you live in a house for 78 years your immune from all the laws of the land. Can't wait till I tell the inspector that
comes on my property because I want to LEGALLY install somthing that needs inspecting by those pesky things called
laws, that I'm immune from him poking his nose around my 78 year old house that is sitting on a 45 degree angle that
it's all good because it's been good for 78 years.

Seriously do you know how silly you sound right now.

Thanks for the advice!
I am absolutely terrified now!
78 years old, and have lived in this (designated historic) house since birth.
Got lead based paint too.
Should I call a demolition contractor tomorrow?

Wish I were a civil engineer.
Oh just remembered .......I am....but an old one (1962), so certainly I know absolutely nothing after all these years.
So "silly" I am!

Your California location pretty much says it all!
How many sheets are required on a toilet paper roll, to comply with California law?

 

[buckeyefarmer]

View attachment 604348
View attachment 604350

I dont see anything leaning at 45°. Oh wait, the door support is at 45.

 

[Kyle_in_Tex]

I still say to do your straightening AFTER you remove roof and wall boards. Then make sure you don't install nails in the same holes.

I would consider marine grade plywood, or paint it with something really good before installing maybe.

 

[EddieWalker]

Sheeting on the roof does two things. First, it gives you sheer strength. Second, it holds the nails used to attach the shingles. For sheer strength, OSB and Plywood are equal. For holding nails, OSB is significantly better. You have to by a high quality plywood to equal the low quality OSB sold at Home Depot to be equal, but if you are going to pay more for plywood, then Zip System OSB is going to be a much better choice. Nothing is better then Zip System!!!!

The problem with plywood is the voids and poor quality of each layer of wood. When you go into an attic an look at the sheeting from the underside, it's obvious how bad the plywood is by how much of it is blown out by the nails for the shingles. OSB is perfect around every single nail. And if you ever replace those shingle and nail over plywood a second time, expect the roof to fail a lot faster then the first time because of how damaged the plywood is.

Here in East Texas, 7/16 OSB is selling for $8 a sheet. It was $14 over the winter and sometimes it will get down to $6 a sheet. Half inch construction grade plywood is $18 right now and it rarely changes in price.

Leaving either outside and exposed to the elements will result in warping, delamination and failure. I'm not sure why anybody would be surprised at this. It's not designed for that.