coloured stripe

Painting, decorating and home improvement tips blog

Tips on using decorator’s caulk

Posted by admin
January 5th, 2009

This is our first tip of the year and may be of use to you if you are planning on having new windows or doors fitted in the coming months. You certainly notice drafty old windows and doors in the depths of the British weather!!
So, onto the tip….
Mastic gun

Tips on using decorator’s caulk
Decorator’s caulk is a flexible filler that can be used to go around windows, doors, ceiling and coving line and along the top of skirting boards. It isn’t any good for filling holes in walls etc, as it cannot be rubbed down like powder filler.

To get the best results from using decorators caulk run it along the crack, not too much (you can always go over it again), once you have a line of caulk use a wet finger to run along the line of caulk to smooth it over.

Once the caulk has dried it can be painted over. If you find once you have painted the caulk with emulsion it cracks, you can go over the caulk with an oil-based undercoat, let it dry, then re-emulsion the caulk.


I have done a review on a caulk that doesn’t crack or craze, I have been using it for a while and the results are good.
Read my Review Of Dunlop Pro Decor Flexible Acrylic Filler Caulk here. And if you would like to buy some for yourself you can buy Dunlop Pro Decor Flexible Filler caulk from here.

Tags: ,
Posted in Decorating Tips | 55 Comments »

55 Responses to “Tips on using decorator’s caulk”

  1. James Says:

    My top tip is.. the faster you move with the gun the better.

    A decorator once told me it is like drawing a line with a pencil if you do it fast it normally turns out straight and if you do it slow its all over the place.

    Date posted : March 16th, 2010 at 8:47 pm
  2. Angelo Says:

    It will be easier if you manage to apply the caulk fast but you still have to smooth it with a wet finger.That’s for sure.

    Date posted : May 2nd, 2010 at 12:14 pm
  3. Andy Says:

    It seems that standard vinyl matt and contractor matt are the culprits for cracking. Not getting problems with acrylic matt at all.

    Date posted : May 8th, 2011 at 5:31 pm
  4. graham jones Says:

    i am a decorater and have had lots of problems with all corks that i have used most vinyl paints and contract matt seem to seperate on the cork more often than not and its not because i havent let it dry properly because i have, i know you can undercoat the cork but then you need to let it dry and go over it 3 times which is time consuming. i never used to get this problem but has been happining for about year and half i think something has changed in the formulation not sure im gonna investegate

    Date posted : November 11th, 2011 at 6:56 pm
  5. PaintyCait Says:

    I find nearly all acrylics and emulsions will crack/craze over caulk with only one coat, but after the second coat this goes. I normally run a brush with thinned paint or primer over the areas that require caulking early in the day to seal if it requires it – like on lining paper where you wouldn’t put the caulk directly onto raw paper – then caulk and apply the 2 coats after that, as opposed to coating, caulking and coating again.
    I also find that I can’t use my finger if I have a whole kitchen cabinetry of ahead of me my finger would be GONE (or needing kissed better at the very least), For large projects we cut a chunk of Spontex sponge and use that…but be very careful not to have the sponge too wet. No kissing required

    Date posted : December 9th, 2011 at 9:03 pm
  6. Michael Says:

    I have skimmed my ceiling and now there’s hairline cracks appearing every where can somebody tell me I can get rid of the cracks please.

    Date posted : January 12th, 2013 at 3:19 pm
  7. Adrian Says:

    I assume you skimmed the ceiling with plaster? What was the reason for skimming it? If there were already cracks in the ceiling did you tape them?

    To rectify this problem you can either fill the cracks with powder filler and hope they don’t come back or paper the ceiling with lining paper for a smooth finish or Anaglypta paper for a textured finish.

    Date posted : January 13th, 2013 at 9:03 am
  8. Steve Says:

    @Michael. I had hairline cracks in bedroom ceiling and used polycell crack free ceiling matt emulsion. I was very sceptical it would work but it really did! Been fine for a year now. Got it from b&q.

    Date posted : January 17th, 2013 at 11:19 pm
  9. Kalli Says:

    Wondering if anyone can help I’m a student studying painting and decorating, a question has come up asking how long caulk should be left till you can paint over it, does anyone have a rough idea?
    Thank you

    Date posted : November 22nd, 2013 at 5:25 pm
  10. Adrian Says:


    It says on the tubes but typically it is between 1-2 hours depending on temperature and thickness of caulk used.

    Date posted : November 23rd, 2013 at 7:35 am
  11. Phil Says:

    My plumber has just fitted a heated towel rail to the wall in the bathroom. To get the old radiator off he had to extract the old 12″ metal brackets from behind a wooden panel between the wall and panel. This left a 2 x12″ slots in the panel which he filled with caulk. There is still a dent showing which is noticeable. Do i apply more caulk before painting or can i use wood filler on top of the caulk?

    Date posted : November 6th, 2014 at 10:50 am
  12. Adrian Says:


    Caulk is only meant for small gaps, between 3-5mm deep. Filling it with some would then filling over the top would have been the best option but as the caulk has already been applied I would use either a wood filler of all purpose filler to fill the remaining gap. The rub down smooth and level before painting.

    Date posted : November 11th, 2014 at 12:24 pm
  13. Ashley Says:

    Just had coving put up and there are a few gaps where wall or ceiling isn’t level. Am I best to chalk before or after painting the room?

    Date posted : January 9th, 2015 at 9:03 pm
  14. Adrian Says:


    Chalk before painting room.

    Date posted : January 12th, 2015 at 2:56 pm
  15. Susie Says:

    We have used calk to fill some holes left where we removed a radiator. We have always used calk to fill holes but this time we have greasey marks. We noticed it after putting a couple of coats of Dulux Matt on the wall so rubbed it all down, applied a thick Polycell base coat over whole area and then put two more coats of Dulux on it. It seemed to be fine but this evening we have been in the room laying the floor and we noticed as we finished the floor that ‘grease’ marks’ were showing again wherever we used calk in the past. What do you advise we do now please????????????? All our hard work is being affected by this. Is it because we have used a matt emulsion where in the past we used silk????

    Date posted : February 10th, 2015 at 10:32 pm
  16. Adrian Says:


    Firstly I never use caulk to fill holes as it isn’t designed to be rubbed down smooth.

    have you tried an oil based product over the greasy marks, this may hold it back, apply and leave to dry before going over it with emulsion. It will take a while to dry as it is on an oil based product.

    You say you use silk emulsion before, this has more vinyl in it so can hold marks back sometimes.

    Useful links:

    How to fill holes and cracks
    Decorating and preparation
    Tips on using decorator’s caulk

    Date posted : February 13th, 2015 at 3:19 pm
  17. Steve Says:

    I used chalk to fill in the gaps in between the skirting and the walls,but now after about 3 weeks,of applying ,it looks as if the chalk is separating from the wood and causing more gaps.Is there a way of rectifying this problem ?

    Date posted : February 22nd, 2015 at 5:38 pm
  18. Adrian Says:


    Was this new skirting board? If so the wood may of dried out, simply re-apply caulk.
    The only other thing I can think of is if the gap was wide and caulk has shrunk when dried, again if this is the case simply re-apply caulk.

    Date posted : February 28th, 2015 at 3:40 pm
  19. Peter Says:

    I’ve previously used Unibond flexible gap filler next to stained and waxed wood. Over time, the stain seeps into the filler. Would this also happen with caulk and if so, how can I prevent it?

    Date posted : April 23rd, 2015 at 2:47 pm
  20. Adrian Says:


    I’m guessing the stain or wax has seeped into the filler as the filler is water / acrylic based and I would assume this will happen with all caulks overtime. Maybe a silicone sealer wouldn’t have the same issues?

    Date posted : May 2nd, 2015 at 2:24 pm
  21. Chris Fowler Says:

    I have used Acrylic Caulk (Decorators Caulk) in the gaps between the skirting board and floorboards. If I paint over it with a Acrylic primer how long roughly will it last or should I have used Silicone?

    Date posted : August 13th, 2015 at 8:45 pm
  22. Adrian Says:


    It should last for years. Don’t use silicone as you can’t paint over it.

    Date posted : August 14th, 2015 at 2:19 pm
  23. Maria Jones Says:

    Used decorators caulk to fill gaps between new skirtings and wall and now discovered it has started to shrink. I have re-applied decorators caulk but the caulk is on the top of the skirting. Can I paint straight over the caulk on the skirting with undercoat then satinwood?

    Date posted : August 30th, 2015 at 11:25 pm
  24. Adrian Says:


    Yes you can paint over the caulk with undercoat and satin wood.

    Useful links:
    Review of Dunlop Pro Decor Flexible Acrylic Filler caulk
    Tips on using decorator’s caulk

    Date posted : September 1st, 2015 at 5:19 pm
  25. Ellie Says:

    New to painting walls. Should I caulk before I paint the walls? I am confused….some sites have suggested that you paint the ceilings first, then the walls, then gloss the skirting boards and door frames.
    I have done the ceiling and now I am about to sand the skirtings and frames. I am eager to get on and paint! I hate glossing and am quite happy to leave it to the end!
    I think caulking looks awful if paint gets smudged onto it and thats very likely in my very amateurish hands! Thats why I want to leave the caulking to the end.
    Many thanks for your help, Ellie

    Date posted : December 8th, 2015 at 1:30 pm
  26. Adrian Says:


    Caulk and fill walls first, get the dirt and dust before painting walls. Paint ceiling first, then walls, then gloss. If you are papering it is slightly different.

    Order of painting an interior room

    Date posted : December 8th, 2015 at 1:35 pm
  27. Christine Says:

    Have just had new tiles put up in my bathroom but because the ceiling isnt level, there is a gap of perhaps 17 to 18 mm in one corner. The tiler has just put lots of grout but that is already cracking. His suggestion is to cover it with UPVC moulding but I really don’t like that idea. Can I use decorators caulk (perhaps the Dunlop Pro Decor Flexible Acrylic Filler Caulk) and if so, will I be able to paint over it with vinyl silk paint? All help greatly appreciated.

    Date posted : January 22nd, 2016 at 10:08 pm
  28. Adrian Says:


    Yes you can use decorators caulk, and yes the Dunlop caulk will be ideal for this. Alternatively you can use ordinary filler (powder filler) to fill in where required.

    Either method will be suitable for painting.

    Date posted : January 23rd, 2016 at 1:35 pm
  29. Mark Says:

    New coving put up in extension. Gaps filled with caulk left for few days and painted. A few weeks later and it’s started to crack. Got builder back who re caulk the room. It’s now happened again. Am I better off using something different than caulk to fill the gaps. Any help much appreciated thanks

    Date posted : February 21st, 2016 at 8:32 pm
  30. Adrian Says:


    Caulk is flexible and the best thing to use, it could be the paint cracking on the caulk.

    Read my review about this caulk here :

    Date posted : February 24th, 2016 at 4:24 pm
  31. Neil Says:

    Hey all,

    Think this could be user error but I’ve caulked some skirting and I’ve found the walls just above (10/20mm) turn brown after a while. It looks like dust has settled and I can’t get rid of it. Have I not cleaned the area properly after appling? If so what’s best to fix?

    Date posted : February 22nd, 2016 at 10:54 am
  32. Adrian Says:


    Have you painted over it? Caulk should be applied and once dry painted. It isn’t a sealer you leave un painted like a silicone sealer.

    Date posted : February 24th, 2016 at 4:22 pm
  33. gav Says:

    Hi there.
    I have replaced my conservatory roof with a lightweight roof.
    The cladding going all the way around the conservatory above the windows that meets the plastered roof was originally sealed with decorators caulk but i have noticed that cracks have appeared in the caulk, would you recommend replacing the caulk with a flexible white sanitary silicone.

    Gav Saxby

    Date posted : March 5th, 2016 at 10:50 pm
  34. Adrian Says:


    If the area is painted you can’t use silicone as paint will not go over it. Some caulk does crack as it dries. You could try painting it with an acrylic primer or non vinyl emulsion and re-paint.

    Date posted : March 6th, 2016 at 4:29 pm
  35. Pete Says:

    Having a new house built and ready to start decorating, just emulsion for now for walls and ceilings, plasterers recommend painters caulking for all wall corners and where ceiling meets walls as minor cracks may appear as plaster dries.

    Suggestions please for type of caulking to prevent cracks from showing.
    Rooms will be papered eventually so need a caulk that will prevent cracks initially and let the wallpaper stick when I can afford to paper (upto 12 months later.)


    Date posted : March 23rd, 2016 at 7:52 pm
  36. Adrian Says:


    I would mist coat the ne plasterwork, then use decorators caulk. Look at Dunlop’s caulk, it’s good stuff. Shouldn’t have any issues with paper sticking at later date.

    Date posted : March 24th, 2016 at 3:46 pm
  37. Pete Says:

    Cheers Adrian,
    Not seen Dunlop’s caulk locally but have read up on subject and bought half a dozen of Everbuild’s CAULK ONCE as it claims to out perform all other caulks. I’ll come back and report on it when I get round to using it.

    Date posted : March 30th, 2016 at 1:11 am
  38. Adrian Says:


    I’ll be interested to hear how it performs.

    Date posted : March 31st, 2016 at 2:41 pm
  39. Dan Says:

    I’ve Painted a feature wall and caulked the ceiling line and corners but haven’t painted over caulk does the caulk need painting over or can you leave it as it is?

    Date posted : April 22nd, 2016 at 12:00 pm
  40. Adrian Says:


    Normally the caulk is applied first and then overpainted. If you leave it unpainted it may discolour in time.

    Date posted : April 22nd, 2016 at 1:56 pm
  41. Bev Says:

    I’ve used caulk to cover lots of problems all over my wall and ceiling….. What should I do before I paint to stop the caulk shining through and/or looking smoother than the rest of the wall?

    Date posted : June 22nd, 2016 at 9:02 pm
  42. Adrian Says:


    Caulk should only really be used for cracks around things that move, such as corners, around door frames and windows, ceiling and wall line. You could try going over the caulk with an acrylic paint first before painting.
    It may well show smoother than the rest of the wall and unfortunately it can not be rubbed down.

    Date posted : June 23rd, 2016 at 4:27 pm
  43. Bev Says:

    What’s an acrylic paint I can use on walls?
    Would pva on the walls help?

    Date posted : June 23rd, 2016 at 10:20 pm
  44. Adrian Says:

    An acrylic paint is for example a water based primer undercoat. Pva wouldn’t really help.

    Date posted : June 25th, 2016 at 4:28 pm
  45. Paul Says:


    Just backing papered a room. Used chalk to fill the seams paper before painting. And then painted with a matt dulux paint.I’ve done this several times and never had a problem but this time the the seams are darker and horrdodus, like the paint is still wet. It looks fine after a fresh coat and all paint is wet but 24 hours later its horrendous! I’ve used silk in other rooms…is this the problem?

    Date posted : July 3rd, 2016 at 10:14 pm
  46. Adrian Says:


    It’s because of the caulk, best to use a fine surface filler in future. It could be the fact you have used matt emulsion this time.

    Date posted : July 9th, 2016 at 1:46 pm
  47. Ray Says:

    Caulk is a most wonderous product, I use the cheapest I can find apply wash back with a real wet sponge (with in reason) let everything dry (well) and paint don’t try it on lining paper joints (big mistake) use dry liners filler prime the paper with a dry lining primer (with a roller) .
    They should change the name of caulk to the the most wonderful masker of sins 🙂

    Date posted : September 30th, 2016 at 4:08 pm
  48. Sophie Says:

    Hi, wonder if you can help please????! I am currently painting floorboards with a black oil based paint. I have filled most gaps between floorboards with caulk but yesterday ran out, so picked up decorators filler (seemed to be similar product). Today the areas where i have used the filler are still tacky and after reading the back of filler it says do not paint for 24 hrs!! Help what do i do? Will it dry eventually?

    Date posted : March 16th, 2017 at 2:45 pm
  49. Adrian Says:


    Leave it for 24hrs and it should be fine to paint over.

    Date posted : March 16th, 2017 at 8:16 pm
  50. E.C.Anderson Says:

    Hi, I am redecorating my house some ten years after it was previously done by ‘professionals’ who got paid a lot of money to do it. I am having a terrible job of trying to remove paint and caulk from the plastic on my windows, in some places it is over the plastic by some 15mm. This is obviously acrylic because silicone remover won’t touch it. Why do professional decorators not have a damp sponge handy to wipe off excess caulk? it only takes a second or two and makes a much neater job. Other than laboriously scraping away at this mess is there any way to soften it prior to scraping it off?

    Date posted : February 13th, 2018 at 1:28 pm
  51. admin Says:


    Once it’s cured its hard to remove. Only warm water may soften it?

    Date posted : February 14th, 2018 at 4:44 pm
  52. Dannie Valasco Says:

    Simply wanna state that this is very useful , Thanks for taking your time to write this.

    Date posted : January 28th, 2019 at 1:16 pm
  53. r joan Says:

    Thought that caulking would be similar to what ever I needed to fill .¬!! This time I made a mistake ,probably rectifiable

    but am now worried that the stuff will not accept Paint or anything else .
    I have watched a professional painter do his work with caulk , and not a word was mentioned as to the suitability of the acrylic to accept paint ,or was he keeping it a secret ??very annoyed about this as it has taken me hours to put right a
    simple job !!!

    Date posted : November 12th, 2019 at 9:19 pm


  1. gap between window and window sill - any suggestions as to how to repair?
  2. Review of Dunlop Pro Decor Flexible Acrylic Filler caulk :: Property Decorating

Leave a Comment


My Paintbrush logo