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    Mould growth on exterior walls

    Painters & Decorators

    There’s mould growing on paint on the exterior of my house. What can I do about this? How can I fix it? How long might it take to sort it out? And what products/treatments do you recommend not only to remove the current mould but to prevent fuutre mould growing? Thanks.

    Asked by Sharon on 18th Mar 2021
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    Best Answer


    "To eliminate this problem,shoot down the walls with a pressure washer or a garden hose if you don’t have one.
    Create a mould killing solution by pouring a gallon of warm water into a bucket & mix with 1/2 cup of household bleach & 1/4 of laundry powder.stir throughly & then mix in 1/2 cup of TRISODIUM PHOSPHATE (you can buy from any DIY store).
    Then sponge the mix onto the mould growth & leave for 15 minutes.scrub the walls down then use the pressure washer or garden hose to wash off & leave it for 24 hours..
    The chemicals in the TRISODIUM phosphate & laundry powder will help lift off the mould."

    Answered on 18th Mar 2021 - Member since Feb 2021 - report
    Lewis Decorators

    "You need to check your gutters or an over flow pipe this could be the problem .
    Once the cause is located and fixed then redecorate the exterior ."

    Answered on 18th Mar 2021 - Member since Jan 2019 - report
    Be Safe Property Maintenance ltd

    "You need to clean off the current mould making sure wall is dry. Apply biocide to treat area and prevent further growth (after application it needs to be washed off before applying paint)"

    Answered on 23rd Mar 2021 - Member since Jun 2019 - report
    Ola Decorator & maintenance

    Get a stain paint primer (zinsser) costly but does the work ..
    Apply as 2 coats : 1 hours interval , but be ready to put the brush in the bin , as is so powerful .

    This will stop reoccurrence of the incident..
    Then you can apply paint after ..

    Hope this help"

    Answered on 18th Mar 2021 - Member since Feb 2021 - report
    South East Construction & Maintenance

    "Is the room affected being properly ventilated (ie. trickle vents in the windows or louvre vent on the walls)? And second quite important - is this the ground floor room?"

    Answered on 10th Apr 2021 - Member since Mar 2021 - report
    Reach N Shine Window Fascia Gutter Cleaning Handyman Professionals

    "Hi use PVA bonding before you paint the wall and have a vent brick put in outside just above the damp proof and as low as possible to dry out any damp in the wall"

    Answered on 18th Mar 2021 - Member since Aug 2016 - report
    A light stroke

    "It's hard to answer without seeing the mould /the area it is in , the cause could be a leaky gutter rain bounce back of the floor or even an over flow pipe. You can clean with an anti fungi spray or use bleach to scrub it away and re paint which usually works , but without seeing if it's any of the above it's hard to stay if that would stop it returning."

    Answered on 18th Mar 2021 - Member since Mar 2020 - report
    Pataki Peter

    "Hi ,

    Black mould is often a result of condensation. When warm moist air comes into contact with a surface at a lower temperature, the moisture condenses on to it. After a while, mould will start to grow on the surface.

    I would defiantly look into the condensation of the house. Maybe install ventilation system could help to prevent future mould growing.

    Temporary solution HG Mould Spray - Please read carefully the instruction before apply.


    Answered on 13th Apr 2021 - Member since Mar 2021 - report
    paul giblin

    "They is a mould solution you just brush it on so get rid of what you can apply the solution wait 24 hours apply solution again and wait another 24 hours then I would get a stabilising solution same again brush that on you can buy thes in any good paint suppliers"

    Answered on 18th Mar 2021 - Member since Sep 2020 - report
    Spencer Bendle

    "Scrape off as much as you can and apply a fungicidal wash."

    Answered on 18th Mar 2021 - Member since Jun 2020 - report

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