How to waterproof my garage?

[Sanderguy777]

Ok, so I think I messed up pretty bad, but I can't do it all over, so here's the issues and what I have heard. Please let me know if there is a better solution!

I bought a house and it came woth a garage. Inspections around here don't include outbuildings (which is mindless imo, and the garage was LITERALLY the reason I even looked at the house at all).SSo when the guy did the inspection, the only thing he looked at was the house and completed ignored the fact that there were massive holes in the siding (fist sized holes in the mdf (why!?) siding that were just covered with a layer of paint.

Anyway, I had to waterproof the shed, so I quickly ran out and got ¾" pressure treated ground contact plywood thinking that I'd just paint it and call it good. I bought the paint too. I then got a 12 pack of Dap AMP caulk/silicone (I know there's a difference) and sealed uo the side I was able to get done before it got too cold (AMP was the only stuff able to handle the sub-freezing temps other than Behr, which I didn't even know made caulk till then).

Now (4 or 5 months later), the caulk has cracked because the ply shrunk.

I realize now that it would have been better to get zip siding and then cover it in siding right away. But I couldn't afford that (and with the tools I had to buy to get all that and some other projects done, I'm at the point where I can't get siding at all).

So, my options as I've heard from several people are (a general contractor doing unrelated work, and my buddy who is a glazier, and my dad)

1. GC recommended vapor barrier, flashing tape, and siding. (No way I can afford that, and I'm not even sure what to look for, honestly. That is way beyond my experience).

2. Friend thinks DOW 795 structural sealant would hold up, but I'm not sure I can remove the caulk enough to make it stick. And it's like $20 a tube, meaning probably $200+ for my 14x22' shed. Manageable cost, but depends on my application and prep, and I'm not sure of either.

3. Dad said just ignore it and paint it. Problem ther is that the new plywood I added last month hasn't dried all the way, so I expect it to peal. And the paint is red, so the primer is pink. I can handle the Operation Pettycoat jokes (I started them when the two ladies at HD told me that they were sorry, but the primer had to be barbie pink so the paint wouldn't need extra coats LOL)

4. My idea is to put boards over the seams between the plywood. Maybe some kind of PVC baseboard that is exterior rated? Then use the 795 to seal those joints. Water would have to get past the sealant, then an inch or two over to the edge before getting into the shed. I can't think of a way that would happen.
Maybe I could use door seal foam on the back of the boards to seal it instead of caulk or sealant?

What would you do with about $900 for this? Plywood is unsealed at the moment, except for the intact caulked areas. No paint or primer yet either.

 

[DGersic]

Pictures might help here?

How do you paint over a “fist sized” hole? That's some impressive film strength.

1/2” exterior plywood isn’t that expensive. With a $900 budget, I’d reside the whole building. Hammer, box of nails. Paint with what you already have.

 

[Youngandfree]

Pics would help. Virginia excludes outbuildings in home inspections also btw.

 

[duneslider]

Pictures would help but T1-11 siding and paint would have this looking like a new shed.

 

[CombatNinja]

You can't cover a fist-sized hole with paint dude. We need pictures of this disaster to make any recommendations. As a learning point, it makes no difference if outbuidings are 'included' in an inspections process according to any municipality, mortgage lender or whoever. If you're buying a property, you can have anything you want inspected as long as you pay for it.

 

[firebirdparts]

I would just ignore it entirely. I am sure you don't think the shed is air-tight, so you are just trying to keep water out of the plywood. I don't know much about your climate, but based on your stated location, I would have thought it was dry. Paint it whenever you feel like it's ready to paint.

I disagree with the opening sentence that you "messed up pretty bad". It's a shed.

P.S. I don't need any pictures.

 

[CombatNinja]

I think he is using 'garage' and 'shed' interchangeably here.

 

[Sanderguy777]

Photo at bottom.

And an update on the caulk. I glanced at the seams yesterday and I think only 1 had an issue. If that'd the case the stuff I used is fine and I can just redo that area.

I'm still looking for ideas on how to better protect the plywood though, just sitting in the elements isn't good foe it, even with GC PT ratings.

Pictures might help here?

How do you paint over a “fist sized” hole? That's some impressive film strength.

1/2” exterior plywood isn’t that expensive. With a $900 budget, I’d reside the whole building. Hammer, box of nails. Paint with what you already have.

I'm sorry of I wasn't clear. I was writing this in a hurry before an appointment.

The old siding was mdf and had fist sized holes that were rotted through the mdf. They painted the panel, then as it rotted the paint was the only thing there. So you could easily just stick finger through the paint.

I used ¾" ply, and I don't see why I need to replace it. The only issue I see with it is that 2 sides have been sitting in the sun and weather all winter, and the other two were just installed in the last month. So I can't paint everything right away.

Pics would help. Virginia excludes outbuildings in home inspections also btw.

It may be all inspectors. I don't see why that would be the case. Who doesn't care if the barn or shed is falling down or has so many termite tunnels half the studs need replaced?

Pictures would help but T1-11 siding and paint would have this looking like a new shed.

I already put plywood up. It doesn't look good, but I thought it would be more durable than t1-11.
If I added that overt top, would it be more waterproof than the plywood?

You can't cover a fist-sized hole with paint dude. We need pictures of this disaster to make any recommendations. As a learning point, it makes no difference if outbuidings are 'included' in an inspections process according to any municipality, mortgage lender or whoever. If you're buying a property, you can have anything you want inspected as long as you pay for it.

I replaced all the old siding with holes, with new ¾" pressure treated ground contact plywood. No holes now, just seams.

I said the shed HAD fist sized holes (from rot, which I didn't mention). Not that I was planning on painting over them. And if you paint it enough, you can absolutely paint over that (I have a friend that paints cars that has pieces of layered paint like 30 layers deep in his studio).

Obviously. But why isn't it part of the norm to inspect them by default? I would have been able to negotiate the price down a bit if I had known what was happening inside the shed/garage (yes, interchangeable).

I would just ignore it entirely. I am sure you don't think the shed is air-tight, so you are just trying to keep water out of the plywood. I don't know much about your climate, but based on your stated location, I would have thought it was dry. Paint it whenever you feel like it's ready to paint.

I disagree with the opening sentence that you "messed up pretty bad". It's a shed.

P.S. I don't need any pictures.

It's definitely NOT air tight. But it's old, and a lot of it is still original, non-pt studs, so I want to keep out as much water as possible.

No, my climate is Midwest, so humid and hot, or humid and wet, or dry and bone chilling LOL. I'm upset that I installed all this without doing more research and figuring out if it would even work. If I had it to do over, I'd definitely just slap up t1-11 and call it a day.

I think he is using 'garage' and 'shed' interchangeably here.

I was, yes. Only one outbuilding, as you can see from the picture. Shop is actually a better term, but it's technically a detached garage.

 

[PCustoms]

This thread is all over the place....

Put battens over the seams and paint the shed. You can add extra battens to make it look like traditional board and batten siding.

If the wood underneath (mdf you stated) has fist sized holes you probably should have stripped it off and sheathed/sided with something like t1-11' smart side or OSB and siding. You still could, but this will be the costliest option.

 

[Renegade1LI]

That looks way better than I imagined, if it was me this is what I would do. Leave the plywood and cut batten strips of 1x3, apply with caulking covering the joints. Next space additional strips equally about 8" apart. Prime and paint it should look great, also use some 1x3 or 4 to make the outside corners, and also paint. White trim and a darker field will look great, like you planned it.

 

[Sanderguy777]

I'm sorry. The way I wrote the original post is confusing, I admit.

I stripped the OLD MDF siding off (it had 3" or 4" holes in the wood, but they were filmed over by the original paint that was somehow mostly intact). I stripped that off and replaced it with the plywood. I thought it would be better than the t1-11, since its plywood and better than OSB.

None of the original siding remains, and ALL of the studs with issues have been replaced as well. The footer stud/sill plate was rotted all around... that's replaced as well.

 

[Sanderguy777]

That looks way better than I imagined, if it was me this is what I would do. Leave the plywood and cut batten strips of 1x3, apply with caulking covering the joints. Next space additional strips equally about 8" apart. Prime and paint it should look great, also use some 1x3 or 4 to make the outside corners, and also paint. White trim and a darker field will look great, like you planned it.

That is actually exactly what I was originally planning LOL. I just ran into the one seam that was faulty and then second guessing whether I'd used the right products. I totally believe the plywood is better than t1-11, EXCEPT that's its about 25% more money per panel, and while it needs paint if it's exposed to weather, it can't be till it dries out and then it's slightly damaged by the sun.

But I think I'll do this. It will last as well ad the original did probably (especially since I added flashing and don't have horizontal boards to catch water (yes, the original did, and that's where the holes came from).

 

[Renegade1LI]

I love the board and batten look, have a garage with it, needs paint but otherwise no issues.

 

[Youngandfree]

Photo at bottom.

And an update on the caulk. I glanced at the seams yesterday and I think only 1 had an issue. If that'd the case the stuff I used is fine and I can just redo that area.

I'm still looking for ideas on how to better protect the plywood though, just sitting in the elements isn't good foe it, even with GC PT ratings.

I'm sorry of I wasn't clear. I was writing this in a hurry before an appointment.

The old siding was mdf and had fist sized holes that were rotted through the mdf. They painted the panel, then as it rotted the paint was the only thing there. So you could easily just stick finger through the paint.

I used ¾" ply, and I don't see why I need to replace it. The only issue I see with it is that 2 sides have been sitting in the sun and weather all winter, and the other two were just installed in the last month. So I can't paint everything right away.


It may be all inspectors. I don't see why that would be the case. Who doesn't care if the barn or shed is falling down or has so many termite tunnels half the studs need replaced?


I already put plywood up. It doesn't look good, but I thought it would be more durable than t1-11.
If I added that overt top, would it be more waterproof than the plywood?


I replaced all the old siding with holes, with new ¾" pressure treated ground contact plywood. No holes now, just seams.

I said the shed HAD fist sized holes (from rot, which I didn't mention). Not that I was planning on painting over them. And if you paint it enough, you can absolutely paint over that (I have a friend that paints cars that has pieces of layered paint like 30 layers deep in his studio).

Obviously. But why isn't it part of the norm to inspect them by default? I would have been able to negotiate the price down a bit if I had known what was happening inside the shed/garage (yes, interchangeable).


It's definitely NOT air tight. But it's old, and a lot of it is still original, non-pt studs, so I want to keep out as much water as possible.

No, my climate is Midwest, so humid and hot, or humid and wet, or dry and bone chilling LOL. I'm upset that I installed all this without doing more research and figuring out if it would even work. If I had it to do over, I'd definitely just slap up t1-11 and call it a day.


I was, yes. Only one outbuilding, as you can see from the picture. Shop is actually a better term, but it's technically a detached garage.

Mortgage company only cares about the home, not outbuildings.

 

[Sanderguy777]

Mortgage company only cares about the home, not outbuildings.

Undoubtedly why they only inspect the house.

 

[mrbill55]

I'm sorry. The way I wrote the original post is confusing, I admit.

I stripped the OLD MDF siding off (it had 3" or 4" holes in the wood, but they were filmed over by the original paint that was somehow mostly intact). I stripped that off and replaced it with the plywood. I thought it would be better than the t1-11, since its plywood and better than OSB.

None of the original siding remains, and ALL of the studs with issues have been replaced as well. The footer stud/sill plate was rotted all around... that's replaced as well.

At this point, I'd wrap the building with the house wrap of your choice, add an additional layer of T-11 siding, stagger the joints, stain/seal/primer/paint it a pleasing to your eye color, and be done with it. Simple, elegant, and not as time consuming as anything else you are thinking of doing.


Bill S.

 

[Sanderguy777]

At this point, I'd wrap the building with the house wrap of your choice, add an additional layer of T-11 siding, stagger the joints, stain/seal/primer/paint it a pleasing to your eye color, and be done with it. Simple, elegant, and not as time consuming as anything else you are thinking of doing.


Bill S.

I have the plywood correctly installed. And was planning on just doing a board and batten look with 1x2 or 1x4 boards.

Why do you recommend the house wrap and a layer of t1-11? I'm not saying I won't do it, but I'm just curious why you think that is necessary. Obviously it would he better protection if I'm ever able to insulate and condition the space, but why is it important at this point?

 

[racecougar]

Is the framing and sheathing in contact with the soil (it appears to be from the sole photo above)? If so, I'd say that is a far greater concern than anything having to do with the sheathing or potential siding here.

You mention a Midwest climate, but your location states "California the thirsty, charred state".

 

[mrbill55]

I have the plywood correctly installed. And was planning on just doing a board and batten look with 1x2 or 1x4 boards.

Why do you recommend the house wrap and a layer of t1-11? I'm not saying I won't do it, but I'm just curious why you think that is necessary. Obviously it would he better protection if I'm ever able to insulate and condition the space, but why is it important at this point?

Regardless of what you may think, pressure treated, ground contact plywood is not waterproof, when left exposed to the elements, the chemicals in the plywood, will start to seep out. In addition, since pressure treated plywood is made with soft wood (to allow the chemicals to be absorbed into the material), water can, and will wick in to the material causing it to swell and warp in a short time. My suggestion, with the sun beating down and drying it out for a week or two, it behooves you to wrap the building to prevent further degradation of the base material, then top it with the T11, which is meant to be a permanent, long term, far more weather resistant/friendly material, stain/seal/paint it afterwards (again, the key here is to place a seal on the T11 to promote longevity). You asked, I answered, ultimately it is your time and money being invested, don't allow yourself to stop now, while you are already half way there and waste the money you have already invested in saving the building. Do it once, do it right, and hopefully, you will not have to do so again.

Bill S.

 

[Sanderguy777]

Is the framing and sheathing in contact with the soil (it appears to be from the sole photo above)? If so, I'd say that is a far greater concern than anything having to do with the sheathing or potential siding here.

You mention a Midwest climate, but your location states "California the thirsty, charred state".

No, it's about 2" off the ground in places. I'm going to dig a "moat" and fill it with gravel so nothing can grow up cna cause water damage, but that hasn't happened yet because of all the house projects that took priority.

Regardless of what you may think, pressure treated, ground contact plywood is not waterproof, when left exposed to the elements, the chemicals in the plywood, will start to seep out. In addition, since pressure treated plywood is made with soft wood (to allow the chemicals to be absorbed into the material), water can, and will wick in to the material causing it to swell and warp in a short time. My suggestion, with the sun beating down and drying it out for a week or two, it behooves you to wrap the building to prevent further degradation of the base material, then top it with the T11, which is meant to be a permanent, long term, far more weather resistant/friendly material, stain/seal/paint it afterwards (again, the key here is to place a seal on the T11 to promote longevity). You asked, I answered, ultimately it is your time and money being invested, don't allow yourself to stop now, while you are already half way there and waste the money you have already invested in saving the building. Do it once, do it right, and hopefully, you will not have to do so again.

Bill S.

I wasn't saying you were wrong, just asking why you thought it needed more. But that makes sense. I'll think about it. I'm not sure I can afford to do it, but I'll look and see. If I do, it will be the most durable building in the country LOL (an inch a a quarter of wood.)

 

[Renegade1LI]

Don't overthink this, if your trying to save money battens and paint will work fine. The garage in the pic I posted has untreated rough sawn pine, 25 years worth no paint and no rot. You can always add house wrap and siding later, just my 2 cents.

 

[DGersic]

The old siding was mdf and had fist sized holes that were rotted through the mdf. They painted the panel, then as it rotted the paint was the only thing there. So you could easily just stick finger through the paint.

I used ¾" ply, and I don't see why I need to replace it. The only issue I see with it is that 2 sides have been sitting in the sun and weather all winter, and the other two were just installed in the last month. So I can't paint everything right away.

Ok, so this is a lot less “shed of doom” than I expected.

With what you have, I’d let it dry out until next year, then build a pseudo board and batten look with some 1x lumber, then prime and paint. Not sure about getting primer to stick to treated plywood, maybe check with your paint supplier about that.

 

[CraigStu]

I am not sure covering it w/ T1-11 is a fix. 'Maybe' it would last longer than the plywood, but to me, that would just mean later on you have a nice looking outer layer w/ rotten plywood underneath it. Here is a thought. How about cutting off the bottom approximately 6 inches of the plywood. Sealing the heck out of that new edge. And putting in some pvc 1x6 or 1x8 pvc boards or similar of anything that is 100% water proof, and paint it tan or grey so it looks like a block foundation wall. You have 3/4" plywood so perhaps you can find something 1/2" thick so there is a step down in thickness at the joint. Or stay w/ 3/4" and cover the joint w/ a pvc 1x2 like you use for your battens.

 

[PoorUB]

For $900 you should be able to put up vinyl siding over the plywood.

 

[Sanderguy777]

Ok, so this is a lot less “shed of doom” than I expected.

With what you have, I’d let it dry out until next year, then build a pseudo board and batten look with some 1x lumber, then prime and paint. Not sure about getting primer to stick to treated plywood, maybe check with your paint supplier about that.

I think it only needs to dry another couple months (thats what the supplier said, and that the paint would then stick).
I don't want to wait that long, as the ply will deteriorate from the sun (I've never seen a concrete number on how much that affects things, but I want to get it going as soon as I can.)

The primer I got will stick fine. It's just that it would feel if the ply isn't dry enough yet.

 

[Sanderguy777]

I am not sure covering it w/ T1-11 is a fix. 'Maybe' it would last longer than the plywood, but to me, that would just mean later on you have a nice looking outer layer w/ rotten plywood underneath it. Here is a thought. How about cutting off the bottom approximately 6 inches of the plywood. Sealing the heck out of that new edge. And putting in some pvc 1x6 or 1x8 pvc boards or similar of anything that is 100% water proof, and paint it tan or grey so it looks like a block foundation wall. You have 3/4" plywood so perhaps you can find something 1/2" thick so there is a step down in thickness at the joint. Or stay w/ 3/4" and cover the joint w/ a pvc 1x2 like you use for your battens.

The ply isn't going to rot any time soon. It's brand new (well, 3 or 4 months old). The MDF original siding is gone.

I don't like the idea of cutting off the bottom, but it is definitely something to think about. (I still plan to do the trench and fill it with gravel, so there will be WAY less splash after that happens.

 

[Sanderguy777]

For $900 you should be able to put up vinyl siding over the plywood.

Where do I get that? And how good does it need to be?

I mean, is there a brand you recommend, or are you saying it's cheap enough in general that I should he able to get it and do it for that price regardless of where I buy it?

 

[racecougar]

Where do I get that? And how good does it need to be?

I mean, is there a brand you recommend, or are you saying it's cheap enough in general that I should he able to get it and do it for that price regardless of where I buy it?

We don't know where you are, as your stated location doesn't seem to be the actual location, but for your shed size, run of the mill vinyl siding from Home Depot should be under your budgeted $900.

 

[Copymutt]

My long term experience w/ board & batten is it will warp, curl, split, pull away & look very rustic. How bout just cover the whole shebang w/ smartside. Its cheaper & superior to t111.

 

[CraigStu]

The ply isn't going to rot any time soon. It's brand new (well, 3 or 4 months old). The MDF original siding is gone.

I don't like the idea of cutting off the bottom, but it is definitely something to think about. (I still plan to do the trench and fill it with gravel, so there will be WAY less splash after that happens.

I think I misunderstand your thread. If you are sure the ply isn't going to rot what is your question? Is it just how soon can I paint it? I saw your comment that there are spots where the ply is 2" off the grass which implies to me there are spots where it is touching. So I was thinking of a way to protect the bottom edge of the ply which is where 90% of similar sidings rot first.

 

[Sanderguy777]

I think I misunderstand your thread. If you are sure the ply isn't going to rot what is your question? Is it just how soon can I paint it? I saw your comment that there are spots where the ply is 2" off the grass which implies to me there are spots where it is touching. So I was thinking of a way to protect the bottom edge of the ply which is where 90% of similar sidings rot first.

Sorry, I have been stupid busy and just replying during tiny breaks.

The plywood is PT, so it SHOULD be able to handle some water and sun. I know that it will break down eventually if not treated with something (paint, siding, whatever).

No point of the siding is touching anything but some stray grass stalks (which I'm mowing and keeping at bay).

I agree that that is the weak spot, but I'm not sure if adding PVC and cutting out the ply is a good idea. I would still need to do the gravel "drain." I'll think about it, though. It's a good idea, I'm just not sure I want to hack off the plywood, but I guess it would just look like a taller foundation, like you said.

 

[DGersic]

The plywood is PT, so it SHOULD be able to handle some water and sun. I know that it will break down eventually if not treated with something (paint, siding, whatever).

PT can go years in the Midwest, summers winters. No worries.

 

[Renegade1LI]

My long term experience w/ board & batten is it will warp, curl, split, pull away & look very rustic. How bout just cover the whole shebang w/ smartside. Its cheaper & superior to t111.

Ever been to the Adirondacks?

 

[Copymutt]

Spent time in the 60’s in the Adirondacks. Lots of moisture & shade. (My experience) is high altitude Co. The intense sun destroys everything from board & batten to skin.