Editing Caulk

{{Short description|Flexible material used in construction to seal joints}}
{{For|the studs installed on horseshoes|Caulkin}}
{{Use American English|date=December 2024}}
{{Use mdy dates|date=December 2024}}
{{More citations needed|date=September 2015}}
[[File:Caulking underneath bathroom sink.jpg|thumb|upright|[[Silicone]]-based caulk on this upturned bathroom sink will spread smoothly, sealing the gap, when the sink is turned over and installed.]]

'''Caulk''' (also known as '''caulking''' and '''calking''')<ref>{{cite dictionary |dictionary=[[Merriam-Webster]] |entry-url=https://www.merriam-webster.com/dictionary/caulk |entry=Caulk |access-date=December 11, 2024 }}</ref> is a material used to [[Seal (mechanical)|seal]] [[Joint (building)|joints]] or seams against leakage in various structures and piping.

The oldest form of caulk consisted of fibrous materials driven into the wedge-shaped seams between boards on [[Boat building#Wood|wooden boats or ships]]. [[Cast iron]] [[Sanitary sewer|sewerage]] [[Water pipe|pipe]]s were formerly caulked in a similar way. Riveted seams in [[ship]]s and [[boiler]]s were formerly sealed by hammering the [[metal]].<ref>{{cite book |first=Walter S. |last=Hutton |title=Steam-Boiler Construction |date=1898 |url=https://books.google.com/books?id=IXtJAAAAYAAJ&pg=PA230 |page=230 }}</ref>

Modern caulking compounds are flexible sealing compounds used to close up gaps in [[building]]s and other structures against [[water]], [[air]], [[dust]], [[insect]]s, or as a component in [[firestop]]ping. In the [[tunnel]]ing industry, caulking is the sealing of joints in segmental [[precast concrete]] tunnels, commonly by using [[concrete]].

==Historical uses==

===Wooden shipbuilding===
Traditional caulking (also spelled calking) on wooden vessels uses [[fiber]]s of [[cotton]] and [[oakum]] ([[hemp]]) soaked in pine [[tar]]. These fibers are driven into the wedge-shaped seam between planks, with a caulking mallet and a broad [[chisel]]-like tool called a caulking iron. The caulking is then covered over with a [[putty]], in the case of hull seams, or else in deck seams with melted pine [[Pitch (resin)|pitch]], in a process referred to as paying, or "calefaction" (cf Dutch ''[[:nl:Breeuwen|kalefateren]]''). Those who carried out this work were known as caulkers. In the [[Hebrew Bible]], the [[Biblical prophet|prophet]] [[Ezekiel]] refers to the caulking of ships as a specialist skill.<ref>{{bibleref2|Ezekiel|27:9|NKJV}}</ref>

<gallery widths="200px" heights="160px">
File:Caulked hull timbers, Spry, Blists Hill.jpg|Dried-out caulking on the [[Severn trow]] [[Severn trow, Spry|''Spry'']], now displayed on shore
File:Caulking tools.jpg|The tools of traditional wooden ship caulking: caulking mallet, caulker's seat, caulking irons, [[cotton]] and [[oakum]]
File:MaryRose-caulking tools2.JPG|A caulking mallet, tar pot and a piece of petrified tar found on board the 16th century [[carrack]] ''[[Mary Rose]]''
</gallery>

===Iron or steel shipbuilding===
In riveted steel or iron [[Shipbuilding|ship construction]], caulking was a process of rendering seams watertight by driving a thick, blunt chisel-like tool into the plating adjacent to the seam. This had the effect of displacing the metal into a close fit with the adjoining piece.<ref>{{cite web |url=http://www.uscg.mil/hq/g-m/nvic/7_01/n7-01.pdf |title=Navigation and Vessel Inspection Circulars (NVIC): USCG |website=USCG.mil }}</ref>

===Boilermaking===
Caulking of iron and steel, of the same type described above for ship's hulls, was also used by [[boilermaker]]s in the era of riveted [[Steam boiler|boiler]]s to make the joints watertight and steamtight.<ref>{{cite book |last=Colvin |first=Fred H. |author-link=Fred H. Colvin |date=1906 |title=The Railroad Pocket-Book: A Quick Reference Cyclopedia of Railroad Information |publisher=New York, Derry-Collard; London, [[Locomotive Publishing Company]] (US-UK co-edition) |page=C‑9 <!-- Not a range --> |url=https://archive.org/details/bub_gb_HhUx85xep4cC |access-date=February 17, 2022 }}</ref>

==Modern use in construction==

===Application<span class="anchor" id="Caulking gun"></span><span class="anchor" id="Caulk cartridge"></span>===
[[File:Caulking, USAF.jpg|thumb|Man applying caulk to [[baseboard]]]]

For bulk use, caulk is generally distributed in disposable cartridges, which are rigid cylindrical cardboard or plastic tubes with an applicator tip at one end, and a movable plunger at the far end. These are used in caulking guns, which typically have a trigger connected to a rod which pushes the plunger, and has a [[Ratchet (device)|ratchet]] to prevent backlash. The push rod may also be actuated by a motor or by compressed air. Similar mechanisms are used for [[grease gun]]s.<ref name="McClintock 2011">{{cite news |title=Squeezing the Best Results out of Caulking Projects |url=https://www.chicagotribune.com/real-estate/ct-xpm-2011-02-15-sc-home-0214-diy-caulk-20110215-story.html |first=Mike |last=McClintock |newspaper=[[Chicago Tribune]] |date=February 15, 2011 |access-date=September 23, 2021 }}</ref>

For smaller applications, caulk may be distributed in [[Tube (container)|squeeze tubes]].<ref name="McClintock 2011" />

====Backer rod====
Backer rod, also called backer material or back-up rod, is a flexible [[foam]] product used behind caulking to increase elasticity, reduce consumption, force the caulking into contact with the sides of the joint creating a better bond, determine the thickness of the caulking, and define the cross-section hour-glass shape of the caulk. The backer rod also acts as a bond breaker to keep the caulking from sticking to the bottom of the opening—called a three-sided bond—with the caulk only adhering to the sides of the opening in an hour-glass shape it can flex more easily and is less likely to tear. Backer rods can also be used to reduce consumption of the caulking by filling part of the joints.

Closed-cell foam does not absorb water and is impermeable.  Closed-cell rods are less compressible and should not be compressed more than 25%.<ref name="Gibb 1980 p41">{{cite magazine |title=Hidden, but Essential: A Technical Review of Backer Rods |url=http://sealnoseal.org/PDF/BackerRod/TechRevBackRods.pdf |last=Gibb |first=J. F. |magazine=The Construction Specifier |date=March 1980 |pages=41 }}</ref> Closed-cell rod will also lose firmness and out-gas if damaged during installation or overcompressed or at sharp bends. The gasses cannot pass through this backer rod and can deform, weaken, and even cause holes (leaks) in the caulk or [[sealant]] as it escapes.

Out-gassing is the reason that open-cell backer rod was developed.<ref name="Gibb 1980 p41" /> Open-cell foam is porous so it will let gasses through which could otherwise cause blistering of the caulk or sealant. Additionally, open-cell backer rod allows air to get to the back side of the caulk or sealant which accelerates curing when used with air-cured sealants such as [[silicone]]. Open-cell rod is more compressible than closed-cell foam and should be compressed 25% to 75%.<ref name="Gibb 1980 p41" />

===Energy efficiency===
According to the [[Consumer Federation of America]], sealing unwanted leaks around homes is an excellent way to cut home energy costs and decrease the household [[carbon footprint]].

Also, sealing cracks and crevices around homes lessens the strain on home appliances and can save time, money and hassle by preventing major repairs.

===Preventing infestation===
Sealing cracks and crevices prevents ingress by rodents.<ref>{{cite web |title=Seal Up! |url=https://www.cdc.gov/rodents/prevent_infestations/seal_up.html |website=CDC.gov |publisher=[[Centers for Disease Control and Prevention]] |date=August 25, 2022 |access-date=September 25, 2022 }}</ref>

==Types==

===Acrylic latex===
The most common type of caulk is acrylic latex, for general-purpose use.<ref name="Dale 2023">{{cite web |last=Dale |first=Timothy |editor-last=Epstein |editor-first=Richard |title=How to Choose Caulk and Sealant for Every Home Project |url=https://www.thespruce.com/select-the-right-caulk-for-the-job-1824846 |website=The Spruce |publisher=[[Dotdash Meredith]] |date=February 21, 2023 |access-date=March 7, 2023 }}</ref> Not only is acrylic latex inexpensive, but it is also the easiest type to apply smoothly and later paint if needed.<ref>{{cite web |last=Petersen |first=Mark |title=Expert Guide for Choosing the Right Caulk for Any Job |url=https://www.familyhandyman.com/list/expert-guide-for-choosing-the-right-caulk-for-any-job/ |access-date=February 17, 2022 |work=Family Handyman |date=August 28, 2021 }}</ref><ref name="Epic Rope 2019">{{cite web |author=Josh |url=https://www.epicropeaccess.com/exterior-maintenance-plan-why-routine-caulking-is-needed-on-commercial-buildings |title=Exterior Maintenance Plan: Why Routine Caulking is Needed on Commercial Buildings |website=Epic Rope Access |date=October 2, 2019 |access-date=March 7, 2023 }}</ref>

===Acrylic tile sealant===
Acrylic tile sealant usually comes in small tubes and is commonly used for wet applications.<ref name="Epic Rope 2019" />

===Polyurethane===
[[Polyurethane]] caulk is very durable and professional grade.{{Citation needed|date=August 2023}}

===Silicone===
{{Main|Sealant}}
[[File:Caulking.jpg|thumb|Silicone caulking extruded from a caulking gun]]

Silicone caulk or sealant is water-, mold-, and mildew-resistant.<ref name="Dale 2023" /><ref name="Epic Rope 2019" /> Technically, when a joint material is silicone-based, it is considered a ''sealant'' rather than caulk.<ref>{{Cite web |title=How to Choose the Right Caulk or Sealant for Your Next Plumbing Project |url=https://www.oatey.com/faqs-blog-videos-case-studies/blog/how-to-choose-right-caulk-or-sealant |publisher=Oatey |access-date=March 26, 2023 }}</ref>

==See also==
* {{Annotated link|Grout}}

==References==
{{Reflist}}

==External links==
* {{Commons category-inline}}
* {{Wiktionary-inline}}

{{Hand tools}}

[[Category:Building materials]]