Thread: Caulking and sealants

Good afternoon colleagues.
Caulking and sealant question.
Which is better? Silicon or polyurethane caulking.

Note: I could not find a specific area to post this question.
I think the should be a section for caulking and sealing questions. Seeing the impact improper or failed caulking and sealants have on home though the decades I thought it might prove to be a good conversation.

Thanks in advance.

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I used to like silicone but I have seen too many failures involving separation from surfaces. For many applications now I prefer polyurethane.

Mark, thank you for opening up the string.
Seeing I think the biggest threat to weather infiltration in exterior wall assemblies is openings due to caulk or sealant loss, next be flashing's, I though I would invoke a discussion on caulk and sealants.

The terms caulk and sealant are sometimes applied interchangeably, but they are actually two different things.

Caulk materials are used for filling small joints [1/4” (6mm or less) Sealants are elastomeric materials used to seal joints where movement is expected(typically 25 to 50%).

Polyurethane has a better adhesion ratio to a host of materials. Silicon caulk is restricted to opening [1/4” (6mm or less) IMO, as well as others.

Caulks and sealants - from: Making Sense of Caulks and Sealants "Caulk is an old boat-building term; sealant originated in home building. Today, some manufacturers use caulk as an all-purpose term and sealant to describe their high-performance products. Most often, though, the terms are used interchangeably, and the products serve the same purpose: to fill gaps between building materials and to keep water and air at bay." (I don't hold much faith in what this site says about much, but this came up on a Google search and pretty much describes the common thinking.)

I look at 'caulk' as being used by painters to fill gaps, seams, corners, etc - not to "seal" but to hide/fill the gaps, seams, corners, etc.

I look at 'sealant' as being used by anyone who is trying to seal anything.

'Caulks', based on the my differentiation above, does not have to have good adhesion, it just needs to 'stay in place' ... 'sealants', on the other hand, need excellent adhesion as that is what seals whatever needs to be sealed.

Likewise, 'caulks', based on my differentiation above, do not need be as flexible as sealants (because the paint over the 'caulk' is not that flexible anyway ... whereas 'sealants' are intended to seal things and need to be unrestrained in movement and thus require a bond breaker rod or tape behind the sealant. Sealants must only adhere to two sides, not three sides, otherwise the sealant will not be allowed to properly compress or expand with movement and will either tear through the sealant or will tear its adhesion from the substrate it is adhered to (either tearing the sealant from the substrate or tearing some of the substrate out with the sealant if the adhesion is better than the strength of the substrate).

The main problem I see with sealants is the lack of use of, or mis-use of, bond breaker rods or tape.

Also, typically sealants require a gap of "at least" 1/4 inch.

If the gap is less than 1/4 inch, all one is really attempting to do is 'fill it' and one might as well 'just caulk it'.

If one is trying to keep water and air out ... or in ... then use a sealant and properly seal it.

Polyurethane Vs Silicone...which is better? In many ways depends on use. Cured poly is paintable, silicone is not. Poly fills expands greater than silicon and fills larger gaps. Poly may seal better as it will adhere to most surfaces. Silicone must have a clean, dry surface (no filmy residue if reapplying) or the seal will break down in short order. In my experience Poly is more difficult to apply, to give a smooth bead and requires mineral spirits for tooling. Though, like everything else proficiency can be accomplished with experience. Silicone, like latex caulk can be tooled lightly with a wet finger but requires clean up with mineral spirits, acetone or other chemicals. Latex is water clean up.
Poly is a little more expensive but has greater application advantages.

1st) Butyl Rubber --- Long lasting and sticks to most everything with minor surface prep and can be reapplied over itself

2nd) Polyurethane ---Long lasting and sticks to most everything with minor surface prep and can be reapplied over itself

3rd) Silicone -----------Long lasting and sticks to most everything with major surface prep but can not be reapplied over itself. To reapply to surface all old silicone has to be removed and surface cleaned and recleaned.

Originally Posted by Garry Sorrells

1st) Butyl Rubber --- Long lasting and sticks to most everything with minor surface prep and can be reapplied over itself

2nd) Polyurethane ---Long lasting and sticks to most everything with minor surface prep and can be reapplied over itself

3rd) Silicone -----------Long lasting and sticks to most everything with major surface prep but can not be reapplied over itself. To reapply to surface all old silicone has to be removed and surface cleaned and recleaned.

Butyl Rubber. Forgot.
Thanks.

I believe that it is just about impossible to get butyl caulk anymore. I think it is the VOC issue.

I was just thinking to myself after reading your post, and it being morning, I love to start my day with some jocularity.
Smile and laugh. It's contagious.

Mark, I am not disputing your point but I was thinking and I am certain Jerry will agree, if you can purchase sub panels I am sure you can purchase butyl caulk.

Why let a little VOC get in your way of sealing something inside your home.

Originally Posted by ROBERT YOUNG

... if you can purchase sub panels I am sure you can purchase butyl caulk.

While a quick Google search finds this: http://www.menards.com/main/paint/ca...39371463662498

... I doubt a quick Google search will find a sub panel our pocketbooks could afford ...

Why let a little VOC get in your way of sealing something inside your home.

Any tubes I have seen are marked for 'exterior use only'.

From Jerry's link Ray.
Caulking your home is great way to protect against damage from heat, water and weather elements. Special attention should be paid to exterior areas like windows and doors while interior areas like bathtubs, sinks, toilets and splashboards need extra protection against water that can seep in and cause costly floor and wall damage.

Originally Posted by Mark Reinmiller

I believe that it is just about impossible to get butyl caulk anymore. I think it is the VOC issue.

Something you wouldn't want....butyl in the eye of the beholder! 😀😀😀😀

Originally Posted by Ian Page

Something you wouldn't want....butyl in the eye of the beholder! 

Butyl is only skin deep ... it's what's behind that butyl that counts.

(bond breaker tape = character)

Originally Posted by Ian Page

Something you wouldn't want....butyl in the eye of the beholder! 

Originally Posted by Jerry Peck

Butyl is only skin deep ... it's what's behind that butyl that counts.

(bond breaker tape = character)

Now, that's being Butyly honest.

Garry, butylyful, bloody butylyful.

Originally Posted by Raymond Wand

Any tubes I have seen are marked for 'exterior use only'.

My understanding is that to have high VOCs the use has to be for a specific use and limited applications. There is a more complicated explanation but that is the basic explanation. Such as enamel paint that is specified for use on metal. Will it work on other things? Yes. Does the label say so? No. Have to know the rules too play the game.

Building Systems for Interior Designers
By Corky Binggeli
https://books.google.ca/books?id=jkX...%20use&f=false

'Caulking compounds used to seal cracks and seams may emit VOCs. Silicone caulking is very safe and stable. Latex caulking is safe once cured, but some types produce odours for weeks after installation from a variety of VOCs including benzene and toluene. Uncured rubber caulkings, such as butyl caulk, acoustical sealant and ploysulfide caulk , are harmful, and may emit formaldehyde, acetic acid, toluene, xylenes and other VOCs.'

Important for those who are sensitive to IAQ.

Originally Posted by Raymond Wand

Building Systems for Interior Designers
By Corky Binggeli
https://books.google.ca/books?id=jkX...%20use&f=false

Important for those who are sensitive to IAQ

Rules are made for various reasons - some are affected more than others, many rules are intended to 'protect' the weakest ... those who are not affected as much adjust those 'rules' to a level acceptable to them.

Hence, we have NASCAR drivers, Indy car drivers, IMSA prototype drivers, Formula 1 drivers, skydivers, scuba divers, people who own pools without barriers or alarms, the list is endless ...

I have no idea how that relates to my post. I was merely pointing out what the product contains. So there are stupid people amongst us, big deal, who cares. It was posted for the intelligent folks to enlighten those who like to know such things.

Originally Posted by Raymond Wand

I have no idea how that relates to my post. I was merely pointing out what the product contains. So there are stupid people amongst us, big deal, who cares. It was posted for the intelligent folks to enlighten those who like to know such things.

Gosh, I must have stepped on your toes on that one.

Garry pointed out 'the rules', you pointed out 'the rules' ('why' the rules mattered ... to some), I pointed out that 'the rules' are there for 'those some', but others are not harmed by 'the why' for 'the rules'.

And that is how that relates to your post.

No they are not rules they are suggestions, better yet its information. (I am sure Garry didn't look at the info as rules per se, at least that's the way I read it.)

Rules - one of a set of explicit or understood 'regulations' or principles governing conduct within a particular activity or sphere: the rules of the game were understood.

Did you see any rules indicating a fine can result because of improper use of caulking; no. Its not a building code violation, if anything it's a life/safety/health issue for consumers, 'that do care' for a myriad of reasons.

Originally Posted by Raymond Wand

Did you see any rules indicating a fine can result because of improper use of caulking; no. Its not a building code violation, ...

Raymond,

You are going off the deep end again - a "rule" does not require a fine, nor does it have to be a "building code violation".

The RULE ... which YOU stated in a previous post ... was 'exterior use only':

Originally Posted by Raymond Wand

Any tubes I have seen are marked for 'exterior use only'.

You then provided support information to back up the rule you posted, and that information, as YOU stated, applied to SOME people (as I stated).

Originally Posted by Raymond Wand

Important for those who are sensitive to IAQ.

I am finished dialoguing with you. You repeatedly twist things to make yourself to be the know-it-all.
You seem to want to argue and make issues and as usual you say I am going off the deep end. It's boring, and I am no longer going to reply in order to stroke your ego.

Hence I am putting you on my ignore list.

Bye.

Originally Posted by Raymond Wand

I am finished dialoguing with you. You repeatedly twist things to make yourself to be the know-it-all.
You seem to want to argue and make issues and as usual you say I am going off the deep end. It's boring, and I am no longer going to reply in order to stroke your ego.

Hence I am putting you on my ignore list.

Bye.

You mean I won't have to read your defensive statements defending why you said something you didn't mean to say?

Nope, only those you would have posted to me - you'll still be posting the same to others.

Raymond, please reconsider you position on this matter.
Your views during a debate with Jerry allows the conversation to broaden. It enriches the topic.
I feel you both were being objective and conversing civilly as to how each of you interpret the same thing.
Nothing wrong with that.

As for putting a member on ignore.
At INACHI I made my position clear about the ignore button.
Bullying behavior by members is in violation of their COE.
The ignore ability allows the perpetrator anonymity. Everyone continues to read his skewed remarks.
Too bad.
So sad.

If an offence was committed, I am certain other members would have spoken out. I certainly would have.

Thanks for the link.
Your the king mate!

Caulks.
The most toxic chemical found in caulks are mineral spirits. Mineral spirits a mixture of toxic, petroleum-based solvents that are classified as volatile organic compounds (VOCs) because (different waste chemicals) are used from the crude oil refining process. When manufacturing mineral spirits, several different substances are referred to as “mineral spirits,” making the specific contents of them often indeterminable.

Seeing we have moved past the days of packing ocum between planks and logs lets move forward.

Adhesive/sealant.

A sealant is an elastomeric material that allows for 25% to 50% movement.
Polyurethane is an organic material.
Silicone is an inorganic material.
The effects of breakdown of silicone and polyurethane depend on the sealant’s chemical makeup.

PU, or for short or sometimes PUR, is not a single material with a fixed composition. PU is a range of chemicals sharing similar chemistry. Polymers plus organic chains joined by urethane or carbamate links. Polyurethane Adhesives Characteristics and uses.

Wow
Really got in here late.
Didn't' read every post

Here is a great resource for everyone.
I do a lot of consulting on sealants and failures of such.

I have more, email if interested