How To Caulk Windows And Where To Caulk Windows

The Handyguys discuss the the energy saving task of caulking windows.


Before we discuss caulking windows, we would like to remind our listeners and viewers of our recent video production on replacing a flush valve.  In addition, we will be re-doing our “Fixing a Dishwasher” video in High Definition for additional clarity on the repair process. We hope to do a video showing some caulking techniques in the near future too.

Window Caulking

Handyguy Paul was asked by a friend “where do you caulk a window?”. That’s a pretty broad question. Is the window wood, vinyl or aluminum? Do You want to caulk it for aesthetics or because of drafts? We will assume drafts. Also, what is the siding material? New replacement windows in old frames? There are a lot of variables. We ramble on in the podcast discussing different places we caulk.

Vinyl windows and vinyl siding
With these types of windows there isn't much caulking to do if they are installed correctly. You can use some painters caulk on the inside where the window meets the casing or the drywall. If it was installed correctly there shouldn't be a draft coming from this area.
Click to see a full sized image. Image © Andersen Corporation

Vinyl windows, if installed correctly, shouldn’t need to be caulked in too many places. Caulking on the interior is mainly for aesthetics. You will caulk where the drywall meets the frame or the casing meets the frame. You can use some painters caulk on the inside where the window meets the casing or the drywall. If it was installed correctly there shouldn’t be a draft coming from this area.

Wood windows with wood siding
Click to see full size image
Click to see full sized image

These windows require a lot more maintenance. All gaps should be re-caulked. If caulking after painting or if you have natural wood, you use a clear caulk. If caulking before painting you should use paintable caulk rated for exterior use.

Replacement windows
Click on the image to see it full size. Thanks to Champion Windows for providing this image.
Click to see a full sized image. Thanks to Champion Windows for providing this image.

Replacement windows are installed in existing wood frames. The windows come as a unit and should be caulked properly when installed. In situations with replacement windows, you have the area between the new window and the existing frame to keep caulk maintained as well as around any old trim.

Handyguy Tips

During a new segment to the show, the Handyguys each provide an important tip for the typical homeowner.

Brian provides some insight on a product from Dap called Seal ‘N Peel Removable Caulk which allows you to temporarily caulk a gap.  This makes sense for gaps between sashes and frames that allow cold air penetration during the winter.
Paul brings up an unrelated tip regarding the testing of a duplex electrical receptacle.  Check out the podcast for more information and be sure to test both sockets when you install or modify any receptacle.
Finally, when shopping for a new home builder, make sure they install quality windows before signing an agreement. Quality windows truly increase the value of a home.


Thanks to Champion Windows for providing one of the pictures. Check them out at

68 thoughts on “How To Caulk Windows And Where To Caulk Windows

  1. Pingback: uberVU - social comments
  2. Over the past few months my electric bill has been going up, and this winter it hit a high point. A friend told me that it might be time to replace my windows. I’m hoping that there would be a cheaper option. Would re-caulking my windows be a good step to take before replacing my entire windows, or just a waste of time and money?

    1. It would depend on the age of the windows, the age of the house, the type of glazing on the windows as well as how well your house is insulated. For example, if you have old single pane glass but have storm windows but no attic insulation then I would add insulation not do new windows. If you have gaps outside definitely seal them. If you house is well insulated but has old single pane windows with no storms then yes replacement windows may make your home more comfortable.

  3. I’ m replacing aluminun windows for impact when installer removed old window the new one was smaller there was a gap between the concrete and the frame of the window possible 1/4 to 1/2 inches they applied screws and a rubber foam and caulking is this correct? I feel that the entire window will come of during a hurricaine (I live in Florida) that is why I’m changing the windows.I was able to see the screws between the frame and the concrete.Any advice will be helpful they are coming tomorrow to continue and I,m scare to death

    Thanks again

  4. I have wood widows with wood siding. Should the top of the drip edge be calked along the bottom of the siding and should the bottom of the trim be calked where it meets the sill?

    1. The drip edge flashing goes under the siding and over the top of the window. It shouldn’t need caulked there if the flashing is installed correctly. If in doubt you can caulk it, it wouldn’t hurt anything.

      The bottom trim should be caulked where it meets the bottom of the sill but not below it. Make sense? Email us a picture and we can try and help out more [email protected]

    1. yes, the outer frame holding the storm window should be caulked where it attaches to the window frame. At the bottom of the storm window frame there are “weep holes” to let out water that could get between the storm window and inside window. those should not be caulked and kept clean so water can drain.

  5. Great podcast! Look forward to the video you mentioned you’d be making. Any advice on the best time of the year to caulk? Can it be too hot out to caulk your windows?

  6. I have a fairly large gap on my inside window where the framing of the window should meet the dry wall. How do I seal this area? should I use some kind of exspandable foam? I am asking because we have had an ant problem this fall and they are coming in around that area.

    1. Shawn – Use some paintable caulk. if the gap is really large you may want to re-install the trim first. It should sit flush. Send some pictures to [email protected] and we may have better suggestions.

      Also, ants wont come in if there is no reason for them to come in. Make sure you clean clean clean. Things like dog or cat food, crumbs, etc will attract them. Eliminate their food and they will go elsewhere. Sometimes even water in the kitchen sink will attract them. Wipe the sink after using it if you get ants in the sink.

      If they are carpenter ants then you may have other issues. Carpenter ants tunnel in wood.

  7. Hi! We have added an addition using James Hardi shingles and Maritech vinyl windows. There are gaps where the shingles meet the vinyl windows. There is no molding trim around the outside other than what is pre-attached to the window. Should we caulk around the outside where the shingles and the window meets and if so, what kind of caulking should we use? Should we use trim pieces to finish the windows and then caulk? The inspector will be coming this week and any timely advice would be much appreciated!! Thanks for the info!

    1. Haley – I cant positively say. In researching the Maritech window construction, if they were installed correctly, there should not be any need for additional caulking. Adding trim would be an aesthetic choice which I would consider doing if your budget allowed.

  8. I recently had single pan windows replaced with aluminum ones and in one bedroom we have wasps getting in thru the window somehow. I’ve caulked the outside and we are looking on the inside now. Please help.

    1. You should only need to caulk outside to keep the critters out. I would check the windows again but also, check the eaves above the windows, siding, crawl spaces, basements, attic, etc.

  9. I just bought a newly renovated cottage. The new windows are vinyl and the siding is cedar clapboards. There is a small gap between all the siding and windows/doors. Does this require caulking.

  10. Hey I have aluminum windows with vinyl siding do I need to caulk the
    outside of the windows or just were the metal meets the wood frame on inside

  11. Hi I have aluminum windows with vinyl siding do I need to silicone the outside of the windows or just the inside wher the wood meets the metal

  12. trying to caulk window do from a old house on the inside

    how do I apply the caulk so its not a huge gob but done neatly and smoothly do I tape it first or what

    1. First, don’t cut the tip of the tube larger than needed. Push the caulk gun, don’t pull it across the joint. Squeeze only as much caulk as needed, no more. If needed you can smooth it with a wet finger. Tape can help if you don’t have a steady hand.

  13. trying to move a bed with mattress and boxsprings frame has wheels but its still hard and heavy to move as hooked to a headboard so I want to use sliders under the wheels but with a lip so the roller will not roll off as I am 80 yrs of age

  14. Vinyl windows and siding. Single pane.I have air leaks all around the edges of the windows in my house. You can feel the draft when its cold enough. I purched this as a HUD home. I was thinking that my geat wasn’t worth a damn then I realized how I can see light around the door sils.I’ve tried weather stripping but the doors are warped likely from where the previous owner attempted repairing this. I’m trying to think of a quick solution to some of theae issues I’m facing my powet bill runs me 350 a month right now and its not a very big home. About 1500 sq ft. I thought about caulking the windows from the inside. I’m curious if they’re even caulked at all. I’m pretty sure this is where I’m losing all my heat or AC

    1. Caulking outside would be my first choice. Interior caulking is usually just for asthetic reasons. For your windows, look at adding a window insulation kit from Frost King to cut down on drafts. For your doors, first try to get them to hang straight, a carpenter can help with that. Then use the correct weatherstripping.

  15. I have a newer house with vinyl window in it, on the outside I have cider trim around all the windows that have a dime thickness gap or smaller all the way around ALL the windows, nothing has ever leaked or had water damage, is it recommended to caulk the gap or not. I live in an area in witch the days a warm/hot and nights are cold. Is that gap there for exspantion and contraction?

  16. I recently purchased a brand new house that was just built. It has vinyl windows and brick around the windows with a brick ledge. We found that there are gaps between the brick mortor and the windows big enough that I can stick a finger in it. We are concerned about critters and water getting into these gaps. The builder told us that it is not necessary to caulk around the windows and that he has never caulked around windows. Should we caulk the windows anyway?

  17. We have to take off our windows in our basement to get a couch inside. The delivery guy said we can cut the caulking down the sides and then reapply when the windows are back in. I have a few concerns… first, what kind of caulking should we get? It looks the same inside and out. It’s a dark brown color. Should we try and remove the old caulking before replacing it? If so, how do we do that? I can send pictures if that would help. Thanks so much!!

    1. Hey Katie – Your choices of caulk will be somewhat limited if you are getting brown in color. Any “window & door” caulk will be fine. You will want to remove as much of the old caulk before applying new. Some caulks wont allow new caulk to stick to them. You would use a scraper and utility knife to remove the old caulk.

  18. Hi. I have an old house and all the work that comes with it. The windows are about 13 years old, vinyl installed on a wood frame, and the outside of the house is stone. The weather has been very mild, but the temperature he dropped suddenly. I took the window unit air conditioner out, but it’s still very drafty. It’s only been about 35 degrees out the last few days. The sill and wall are cold to the touch. Is it too late to caulk for the season, even just on the inside? I know there is no insulation in the walls, but that’s a project for another day. If it’s too late to caulk, any suggestions aside from plastic wrap? (my cats usually rip it down) Thank you!

    1. Step one would be to caulk OUTSIDE. Caulk ideally when its in the 50s or higher, we should get a few more warmer days depending on where you live. Also, make sure you lock the windows, that helps with drafts.

      If you still have drafts, the old time way to deal with it would be to use heavy drapes and cover them. My parents had winter drapes and summer shears for their windows. Other options – caulk inside around the trim. The plastic wrap works fairly well if you can keep the cats away from it. Frost King is my go to supplier for that. There are also now removable caulk products you can use and then pull off in the summer.

      If you really want to get fancy – You can remove the trim inside the house and then use a low expansion spray foam in the cavity behind the trim on the sides, above and below the window. You could also just use fiberglass in those gaps as well.

      Good luck!

  19. I removed all the paint from Likit Alumimun sliding glass windows sills. I caulted the all around the frame where it meets the drywall. Do I need to cault the window sill where it meets the frame. (all along the back side of sill).
    Looks to me as thou it is one unit with no need to cault, just not sure. /Users/NoreenTeter/Desktop/IMG_3160.JPG

    1. Interior caulking is usually done to prevent drafts or for aesthetic reasons. Painters caulk is often used inside to cover any gaps or cracks before painting. If it is interior and looks okay then no need to caulk.

  20. We just had a replacement vinyl window put in. We have vinyl siding. The installer caulked head, jambs and sill between the new window and the existing j-channel. I am concerned any water that gets behind the j-channel will be trapped and come IN the house. Is it a legitimate concern? I have no way of knowing how the home-wrap has been installed, as no siding was removed/replaced during the new window install.

  21. Hello!
    I live in the basement level of an apartment complex and I get all sorts of bugs throughout the summer. Beetles, centipedes, spiders, and even crickets. I am deathly terrified of bugs so this has become a huge problem for me. I used industrial bug spray around all of the windows and door but they still got in. Then, I put plastic over the windows and it seemed to help a little but the problem still persists. To make matters worse, the draft in the winter is terrible! I can sit there and watch the wind blow the plastic back and forth… Since replacing the windows isn’t an option, it seems my last resort will be caulking. My question is do I caulk according to the photo above even though the windows are aluminum and the building is brick outside/drywall inside? The windows slide sideways and there is no siding if it makes a difference. (Sorry if that’s a silly question, I’ve never caulked before) Thanks in advance!

    1. Caulk around the frame outside. If the windows are still drafty you might be able to use something called “removable caulk” or perhaps “mortite”

      Mortite –
      removable caulk –

      Either of those will allow you to seal the window shut yet allow removal in the future.

      You may also have a drafty sill (where the wall connects to the foundation). You can use regular caulk or expanding foam (if a large gap) to seal up that area if needed.

  22. I have a concern I’m hoping I can find some help with… We purchased a new home about 9 month ago.. This spring we have noticed Spingtails and small spider come through the bottom of the window sill inside the home. I do notice the same critters outside the home… I noticed on the outside of the window frame where it meets the siding that it is not caulked. First SHOULD that have been caulked on the exterior??? the builder claims they do not caulk the areas of the home with siding. Would caulking help to prevent with bugs?? Second.. IF this should have been caulked should we been concerned with water getting into the walls?

  23. Thanks for the reply. Is it OK to caulk the underside and the topside of the frame inside the home to keep critters from sneaking in through those areas?

  24. We bought a house built in 1962. Some the windows have gaps that I will be filling with a good quality caulk from the outside, but my question is this – if there might be water infiltration through the gaps, should I try to spray anything inside in case of mildew or mold, or simply caulk the exteriors and trust they will dry out over time (if they are wet). We live in a very humid location in Florida.

  25. Should we caulk all four sides of a window? Or leave the bottom uncaulked so moisture that somehow gets inside the window can evaporate or drip away?

    And is the answer to my questions the same, whether we’re talking about caulking the boundary between window and its surrounding wood trim versus the boundary between that wood trim and the wood siding?

    I had my 2002 manufactured/mobile home in mind when I asked those questions. It has aluminum windows, and both trim and siding are made of pressed wood.

  26. The people that installed my replacement windows did a very sloppy caulk job on the enterior of one of them. Upon removing the caulk, I found what I thought looked like a large gap. What is an acceptable gap width and depth for the bottom interior of a replacement window? They I’d fill the gap with a spray foam but there are places where the caulk I removed was over an inch deep and more than a half inch wide.

    1. Interior below the window often does have a largish gap. That gap us usually just filled with fiberglass insulation and covered with trim. send us a picture if I’m not understanding.

  27. I just replaced the brick mold around my aluminum windows. I need to know where to caulk. Around the entire window is J channel/ vinyl siding, then the brick mold and then the metal/aluminum window. I do have a small gap between window and brick mold but not between J channel and brick mold. I was told by two different people two different places to caulk. Don’t want to trap water but do want to keep it out.

    1. Brick moulding to window should be caulked (If I’m envisioning what you describe correctly). If the window is flashed properly then no need to caulk in the j-channel.

  28. When we replaced our windows with vinyl inserts the step of calking the window to the frame before screwing them in was skipped. Should we remove the window and correct it or just proceed with calking around the outside? Thank you.

  29. CAULKING WINDOWS- I have an old home built approx 150 years ago with rope and cord Windows. Contractor replaced Windows with double-insulated vinyl Windows. Walked off job and did not finish painting job. I am getting bubbling on walls under Windows inside house on sheetrock. Don’t think contractor caulked Windows. Should I scrape out all old CAULKING away from exterior Windows and sashing above Windows and put all new CAULKING in all appropriate places on Windows? Will that fix the problem?

    1. I cant imagine a replacement window not being caulked. They are normally caulked between the new vinyl and the old jambs/sills. Essentially everywhere the new abuts the old. If that is caulked then your water leaks are from old work, not the new. A replacement window relies on the use of the original jambs, sills and original flashing. Those original components need to be in good condition, not leaking.

  30. hello, I recently had the exterior of our house painted . The ext. siding is a product known as texture 111 ( text one 11 ) The trim around the windows is brick molding . When the painters were done and left , I was looking over the job and noticed that there was no caulking under the sill of the windows where it meets the siding. I called and spoke with the painter and asked him about the no caulk under there. He said that there was never any caulking installed there when the house was built. He said that maybe it had something to with the way the windows were installed originally and that he did not want to change any ventilation issued by caulking under the sill hangover . All of the windows are caulked the same way. The top and two sides , but not the bottom. My question is , should there have been caulking under the window sill that hangs out over the siding by about 2 inches , or do I leave it the way that it is , and not disturb the original construction ? THANK YOU

    1. It cant say for certain without knowing how things were built. There are definitely circumstances where the bottom of the sill should not be caulked. The risk is that water could get trapped and cause rot.

  31. We just had new windows installed & the caulking between the stucco & frame has loosened & has hairline openings. I’m a neat-knick & think it’s a sloppy job. How can I be sure? The windows were installed two months ago.


    1. Materials expand and contract, some at different rates. When one material expands and what its attached to doesn’t then you may hear noise as one material rubs the other. It sounds like popping because it does it all at once versus gradually. Not sure I explained that well but I hope you get the idea.

      I haven’t heard of windows doing this before, usually its baseboard hot water pipes or radiators. If you have baseboard hot water heat right below the windows I would think you might be hearing that, not the windows. If it really IS the windows. I’m not sure what you could do.

      1) Put up heavy drapes. This will keep your room a more stable temperature and also block some of the sound the windows are making. It may also lessen any expansion/contraction they do thereby reducing the noise.

      2) Put up storm windows. You didn’t say if you have storm windows or not. They are more common on older homes. A storm window adds another layer of glass better insulating things and cutting down on drafts. This, like the drapes, may help minimize any expansion/contraction and reduce the noise.

      3) Put in new windows. A drastic step for sure. I’ll go out on a limb and guess these are very inexpensive plastic vinyl windows. Replacing them with a high quality window may solve the issue. Maybe a aluminum clad wood window would give you better results.

      Good luck

  33. Hello, great article!

    My house is a couple years old and with the right wind direction and speed (about 40-50 mph) I get the high pitch buzzing/howling from the window. It’s a single hung double glass vinyl window.

    There is definitely a small draft in the top left corner in this wind, and I can see the interior caulking is pretty much completely let go.

    I read in your posts that the interior caulking doesn’t really help much, but I find the air/sound is coming in from where the caulking is in the worst shape.

    Do you think these windows are installed correctly, is there is a way I can check the caulking on the outside too without taking the vinyl siding off?


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