FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

Exterior Caulk-what’s good?

Crawdad | Posted in General Discussion on October 31, 2007 12:43pm

Whats the best exterior caulk to use?  Latex,poly,silicone, paintable silicone, the choices are mind bogling.  I’m just looking for something that will hold up well around my new window installations etc.  Thanks

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. User avater
    BarryE | Oct 31, 2007 01:28am | #1

    http://forums.taunton.com/tp-breaktime/messages?msg=96209.1


    Barry E-Remodeler

     

  2. DanH | Oct 31, 2007 03:39am | #2

    The main problem is that good caulk, like good tools and good appliances, lasts so long that even if you can remember what it was you can no longer find the same stuff when it comes time to replace it.

    If your view never changes you're following the wrong leader
  3. WINSTALL | Oct 31, 2007 02:59pm | #3

    np-1, or Sika-flex. I use nothing but urethane based caulk. I love it. It holds up well and paints well. Bridges large areas and tools very smooth.

  4. Crawdad | Oct 31, 2007 03:34pm | #4

    thanks to all

  5. csnow | Oct 31, 2007 06:47pm | #5

    I think it depends a lot on the application.

    For example, polyurethane caulks are unbelievable performers, but are expensive and difficult to tool.  It's worth asking- Is this a critical joint, or just for appearance?  Exposed to extremes or well protected? 

    Also, prep and technique are big factors no matter what you are using. 

    For example, the instructions for the Pella windows I just installed specificied a 3/8 gap between the trim, use of backer rod, and poly caulk.  Also it specified that the trim should be pre-primed caulk edge  That was surprisingly thorough advice.

    The backer rod ensures that the bead is not too deep, allowing more stretch.  The 3/8 gap ensure that the bead is wide enough to support stretch from expansion/contraction.  The primer ensures a good bond.

    1. Crawdad | Nov 01, 2007 12:38am | #6

      Critical joint, between azek trim and Andersen window.   I have read about caulk backer jount material numerous times but haven'seen it anywhere.  Where in the heck do you get the stuff?

      1. User avater
        Gene_Davis | Nov 01, 2007 01:28am | #7

        My recommendation for your app is OSI Quad, which is available in colors that match most all of the Hardy factory paints.

        View Image

        1. DaveRicheson | Nov 06, 2007 07:11am | #16

          I don't know how Quad performes on Hardi, but on steel siding in direct sunlight it only lasted about 4 years for me. On the full shade side it has gone over 6 years so far. I have also used it at work on an alum. flashing and EIFS joint. Same story, southern direct sunlight exposures are failing.

          I use to be a big fan of OSI Quad, but experience is changing my mind.

           

          Dave

      2. User avater
        BillHartmann | Nov 01, 2007 04:41am | #10

        Every home horror store and hardware store that I have been in has backerrod.But for some strange reason it is by the weather stripping and not the caulks..
        .
        A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.

        1. DonCanDo | Nov 01, 2007 12:32pm | #12

          I've got to take a better look, but I have NEVER seen backer rod at the big box and the one time I asked for it at a lumber yard, they didn't know what I was talking about.  I always just assumed that using backer rod was one of those really good ideas that nobody actually ever did.

          1. Crawdad | Nov 01, 2007 04:25pm | #14

            LOL kinda what I figured too-  thanks to all who replied with info

          2. BryanSayer | Nov 06, 2007 07:28pm | #18

            If they don't know what you are talking about when you say "foam backer rod" ask for "caulk saver".Places that specialize in waterproofing materials may sell it by the foot and have more choices as to diameters.

        2. Crawdad | Nov 01, 2007 04:20pm | #13

          Aha, by the weatherstripping.  I'll try that today.

  6. ted | Nov 01, 2007 03:22am | #8

    my first choice is polyurethane. 2nd is some commercial stuff called Tremco Mono which is essentially a butyl rubber type sealant that has some proprietary ingredients that make it easier to tool. I use silicone on rare occasions.

  7. User avater
    Jeff_Clarke | Nov 01, 2007 04:36am | #9

    http://www.npcsealants.com/900.htm

     

    Jeff

  8. User avater
    Dinosaur | Nov 01, 2007 05:52am | #11

    View Imagehttp://mulco.ca/En/Industriel/produits/Produits_c_ext.htm

     

    SUPRA is an industrial-grade thermoplastic sealant. It's unbelievably smooth to work with; if you have a good hand with your caulking gun, you won't have to tool it at all. The cartridges are certified bubble free, and it comes in about 50 colours. The stuff lasts over 20 years without degrading in stretch or adhesion, and does not harden or require chipping or scraping to remove even after many years in an exterior application. Generally only available at trade suppliers, not big boxes or hardware stores.

    The consumer version of this product is called FLEXTRA, and is available in most big-box stores. It works and performs much like Supra but isn't available in as many colours, and I don't remember if the cartridges are certified to be bubble-free.

    Either of these products will change the way you think about caulking forever. I will no longer willingly use any other product except for specialty applications such as chimney flashings (high-heat silicone) or screw-down steel roof (butyl).

    Dinosaur

    How now, Mighty Sauron, that thou art not brought
    low by this? For thine evil pales before that which
    foolish men call Justice....

  9. rogue | Nov 06, 2007 06:34am | #15

    As far as the backer you're referring to, we call it rod-stock around here in. If your hardware store doesn't have look for someplace that has brick supplies, 'cuz they have to have it for their expansion joints.

    As far as the best caulk for all around exterior use, I wouldn't consider anything but pro geocel. It goes on well, and neat in hot or cold and I've pulled stuff off that was over ten years old that was still flexible and no signs of wear.

  10. Toolpig | Nov 06, 2007 02:57pm | #17

    Been using DAP "Sidewinder" for fiber-cement siding.  Best I've ever used!  Cleans up easy, paintable and stays flexible (basically turns to rubber when cured).  Much better than latex IMHO.  Tube says you can apply it in "sub-zero" temps, which is important here in the northeast.

    Geocel 2300 is another good bet, especially for roofing applications.

    TP

     

    Toolpig (a.k.a. The man formerly known as "Toolfreak" and "Toolfanatic")
  11. blackdiamondcaulking | Mar 05, 2025 11:54pm | #19

    For exterior window installations, silicone or polyurethane caulk are your best bets for durability and weather resistance. Here’s a quick breakdown of the options:

    100% Silicone – Excellent for waterproofing, flexibility, and longevity. It won’t shrink or crack but isn’t paintable.
    Paintable Silicone – A hybrid option that combines the durability of silicone with the ability to be painted. Good if you want to match trim color.
    Polyurethane (PU) Caulk – Extremely strong, flexible, and weather-resistant. It adheres well to various surfaces but can be harder to work with.
    Acrylic Latex – Easy to apply and paintable but doesn’t hold up as long in extreme conditions compared to silicone or PU.
    For long-term durability, I’d recommend GE Silicone II, OSI Quad Max (polyurethane), or DAP Dynaflex 230 (paintable hybrid). If your area experiences harsh weather, silicone or polyurethane will last the longest.

    What’s your climate like? That might help narrow down the best choice.

    For more you also visit https://blackdiamondcaulking.com.au/

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

FHB Summit 2025 — Design, Build, Business

Join some of the most experienced and recognized building professionals for two days of presentations, panel discussions, networking, and more.

Featured Video

Video: Build a Fireplace, Brick by Brick

Watch mason Mike Mehaffey construct a traditional-style fireplace that burns well and meets current building codes.

Related Stories

  • Podcast Episode 686: Brick Steps, Ground-Source Heat Pumps, and Greenhouses in Nova Scotia
  • FHB Podcast Segment: Efficient HVAC for a New Build
  • Affordable Scans, Accurate Plans
  • FHB Summit 2025 — Design, Build, Business

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers
  • Issue 327 - November 2024
    • Repairing Damaged Walls and Ceilings
    • Plumbing Protection
    • Talking Shop

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data