Woodgrain cementboard lap-siding joints problem

This lady from out of town who I manage her local rental for:

On her own personal house where she lives, she has that siding I mentioned in title. Some handy or carpenter guy who was at her house to do repairs, noticed she had exposed butt joints on the lap siding. So he tells her they shoud be caulked.

So he caulks them. 6 months ago.

Then, he discovered his caulk job was too noticeable up against the pre-finished sand color siding (she chose sand color as it comes in various maintenance free colors). So then the guy tells her he has an idea -that he can paint the caulk to match the siding. So he does. But now the whole works sticks out like a sore thumb, and the lady wants to know if I have any answers.

I told her that I am not familiar with that siding, since they keep inventing new stuff. And I am not doing contracting like I once was up til 15 years ago. I told her I know asbestos-cement board siding very well. That with that, you did not caulk the butt joints. Instead you installed pre-cut felt strips (say 3 x 12) between the butt joints, to overlap the row before, so technically, no water could run down behind the siding and mold or rot wood or leak down behind the flashing above doors and windows.

But I'm not sure what the prefered method is with horizontal lap cement board siding. I told her that often people think caulk is a cure all for joints. But depending on the material, and if it can expand and contract with heat, it coud still crack down the road, and require additional maintenance.

On that pressboard horizontal lap siding, that once was so popular, that has had class action lawsuit agaisnt it, you were given I think they were aluminum spacers that went at each butt joint.

Or, do they allow water to pass thru the butt joint and simply rely on some sort of sheeting material behind it, and not worry about it? Or, are you suppose to say use a spacer designed for this siding?, or felt-paper strip it like the method I describe? And do you think perhaps it might be back there?

Now that I have described what it is -how do you get off excess caulk and paint without say having some cleaning agent/solvent leave a permanent residue/stain into the surface of the cement board? Since I am unfamiliar with the material and it's outer surface, which is the factory impregnated color only (she says it is smooth, but with woodgrain pattern) -could a cleaner soak in and permanently stain that type of siding, or not?

What would you do to try to get it back so that at the worst, only the crack had cauk/paint in it, and not the slobbered extra amount caused when he ran over it with his thumb and it squirted out on each side of the butt joints?

 

I would contact the manufacturer and talk to a rep. The pre-colored caulking and end-grain-of-board paint usually comes with it. As well as installation instructions. (Try the web.) Be safe, GBR

 

Thanks. I do not know who that would be though, and I doubt the home owner lady does either. Perhaps web, lumber yard or bigbox store would have general info on this and standard procedures, and mfg. phone number(s). I'll let you know what comes of this.

 

Ec, she probably has a worse look now than she did with the seams showing. With Hardie, the seams exposed are directly on top of a solid piece so no water infiltration will take place. IMO they should have left well enough alone.

 

A solid "piece". A solid piece of what? I haven't worked with that siding. But am trying to picture how that be different than any other lap siding. I guess I don't understand how there'd be a solid piece under the vertical butt joints.

Or are those butt joints sort of ship-lapped or something?

Please explain or make drawing or something. That be fun for all of us to look at.

 

I didn't explain very well. The Tyvek, or other barrier is solid behind the siding, so the small gap that may allow infiltration won't allow enough to do damage. Caulking them as you go and painting all at once is the best solution, but after the fact is going to cause poor looks. And for the laugh of the day, you want me to draw something???

 

Here is instalation instructions as per where you live.

HardiePlank Lap Siding

I do know you have to paint the ends after a cut, to seal them from moisture (product wicks water), before you caulk in my locale. Waiting for Chandler's drawing ( be sure it's not copywritten). Be safe, GBAR

 

Yeah, painting the edges is important. Most of the work I have been doing in the past few weeks is repairing the lower 3 or 4 boards of chimney chases, dormers, etc. that were jammed onto the shingles raw. Wicking was terrible. The cement board doesn't rot, it delaminates as GBR says

 

Yeah, if the butt joints were not caulked, the best practice is to have a flashing behind the joint. (figure 2 as shown in the directions GBR linked to... which alludes to the fact that the joint flashing is required by certain local codes)

Even if there is Tyvek behind the siding, you don't want water getting into those joints, sitting on top of the rows of hardiplank, because the back side of the hardiplank is only primed, and won't hold up to repeated wettings. (same reason why the siding is kept 2" off of roofs, sidewalks, etc... to promote drying and to help avoid repeated wetting and wicking) That sort of installation (without joint flashings) is certainly allowed by most codes, but works best only if the joints have been caulked. Even then, I think it's a bad practice to have no joint flashing, because IMO, what happens when the caulk fails, and no one notices? It would cause the siding to fail prematurely.

So if there was a joint flashing then the caulk was unnecessary. Many contractors (and homeowners) think it looks better without caulk. Others prefer to have the caulking for cosmetic reasons. But if the caulking looks bad, then that logic kind of backfired.

 

Gee. That's too bad that you can't draw?, I presume? I actually got jobs by drawing out 3-d (view)drawings of what someone's addition would look like. And they were impressed and gave me the job.

A local competitor got kind of mad at me when he knew I was doing that. So he got defensive and said I was actually foolish for doing that, because people could take my plans and let someone else do the building. He also said he just highballed figures to people, for them to 'take it or leave it'. And he said he surprisingly still got many of those jobs.

 

Or, like I said in an earlier post, you coud have many of the butt joints over a window, and have the water get in the cracks, run behind the siding, and maybe find it's way back in towards the inside of the house when it gets to the top of the window. That screnario happened on a house with asbestos shingles on it and it did some pretty bad rot damage.

 

Ahhh. I read some of it for my locale. They do not recommend caulking the butt joints and want to see you use a rather wide piece of flashing. They are not responsible for water infiltration, it also says.

Now, based on you guys knowledge of the consistency of this Hardy stuff -what should the lady do to get off the raised caulk and paint on those joints? Can she even say scrape, and then later paint the whole siding? She says it is already prepainted. But you can paint the stuff, right? You can asbestos cement siding. In fact, that stuff really holds the paint good, if prepped right.

 

It's hard to give a suggestion without knowing what sort of caulk was used. Most latex caulking will cut fairly easily with a knife, whereas urethane sealants will be much stiffer and harder to cut. I wouldn't think that he used silicone.

I'd suggest light scraping with a plastic scraper or plastic putty knife as a first step. If that doesn't want to take it off, I think you'll probably have to risk abrading the surface with something harder... a metal putty knife or chisel. If you are careful, you could also try using a wire brush attachment on a drill or a sandpaper disk on a grinder If the finish on the siding is abraded, it must be primed, using factory approved primer and 100% acrylic topcoat. (see their paint list for approved paints).

I do not think that using any type of solvent would be a good idea, as it could soak into the siding and contaminate it. Future paint adhesion would then be called into question. The least damaging solvent to use would be denatured alcohol, and I doubt it would help much, aside from cleaning off any goop that's soft.

I hesitate to recommend using a heat gun to soften the sealant, but that might be an idea to soften the caulking if it's hardened to the point that you can't scrape it off easily.

The only way to match prepainted Hardiplank is with the factory paint... and that may even be hard to do because of the various factory authorized finishers around the country. The best bet is to repaint the entire house.

The guy must have made a holy mess out of those joints in order for you to be considering removing the sealant.

 

Very good post, full of ideas. I like the heat idea + perhaps plastic putty knife may have best luck with heat. No solvents = yes, most certainly you make good point to remember.

Well, the lady is a perfectionist who believes in getting quality work for the money. She says that you simply can 'see' the joints now. Whereas before there was just the joint. He was the one who talked her into this, because his reasoning was that water was going to go in the cracks and cause damage.

Do you think that butt joint 'flashing' that is used is metal? If so, one could experiment with a razor knife in a crack and try to score in the crack and feel if one is scoring metal, or instead if it feels that one is 'cutting'. I'd imagine aluminum, rather than galvanized would have been used?, which would rule out using a magnet to test with.

 

You might be able to examine the bottom row of siding and look underneath the laps... lightly pry with a putty knife... and see if you can find any evidence of flashing. I would highly doubt that any flashing was used. If it was, I would expect it to be square pieces of Tyvek, #30 felt, or similar. I would not expect metal to be used. Aluminum can react with the alkali in fiber cement and it's use is not recommended.

If you cut out the caulk from the joints, you'd set your blade depth so as not to cut the flashing or the building paper that covers the sheathing.

If the caulk is not messy, I wonder if smoothing it and repainting is all that is needed. I would imagine that the joints stand out mainly because of the touchup painting that was done. If the caulking is messy, well, we both know that a caulking gun in the hands of an unskilled person is a dangerous thing.

 

She said the caulk was like raised, as if he ran down each joint with his finger and it flared out past each small joint.

I have a feeling she would live with caulk in the joint, if it were confined only to in the joint and not overlapping the joint by say 1/4 inch or more on each side. I asked her to send me a photo, but she told me that I am describing it to her perfectly.

Good idea about the bottom run of siding. Is this siding crunchy and snaps real easy if bent slightly? How thick is it?

 

It's 5/16" thick. It's not as brittle as the old asbestos-slate siding, but it could break if you pry too hard behind it... especially at the bottom corners of the joints if they have been face nailed. If it is blind nailed, you should be able to pry it out enough to look for the flashing. But don't pry it too far or it will loosen the siding on the blind nails, and then it'll flap in the wind.

If the siding isn't gooped out too badly, you might be able to clean up the joints with a razor scraper and remove any "raised" areas of sealant.

 

I was going to go to my bigbox store to see what the stuff looks like to get a handle more on what any tool on that siding might do. I bought a vertical blind, put it in my vehicle, but then forgot to go back in the store.

Oddly today, on our noontime radio show where they feature a local building contractor that is like a doctor with his overall knowledge on many materials and applications and techniques - they were talking about a siding he says is superior to the cement-fiber siding. He said the siding is called LP(brand) "Smartside". He said it is more durable than cement-fiber siding. i guess it even has a zinc coating on it, making it impossible for milew-mold to grow. It is even Formosa? termite proof. 50 year warranty. Same material used to do soffit and fascia and other stuff. Something interesting to look into.