Get that flush with the surrounding plaster and allow to dry. Cracks can be repaired with mesh or specialist methods before rendering over. Apply it to the hacked off area,let it dry and render over. Short answer. For example, the first thing I do before I apply the render is to give the wall a light spray with water. Do I need to apply external PVA to the wall prior to the base coat? Community Answer. Do you need to PVA walls before tiling? what i would do is weak pva over the bricks to seal it, then when dry a thick pva & render when tacky with 4 sand & 1 cement for both coats. I have used PVA glue in render with no adverse effect, paint some on the wall first, as well as putting it in the mix. New rendering should not be applied directly to ‘dry’ surfaces which have not been coated with PVA or Gripbond type liquids which stop the render drying out too quickly and helps adhesion. I must say I was realy suprised at how hard the mix with PVA in it went.. The scratch coat is the first layer of render to be placed on the wall. This is typically up to 10 mm thick. ... Before rendering a wall, chip away the old render using a cold chisel, and spray the wall with a garden hose to prevent the rendering mortar from drying out as you apply it. Regards. Then just before the end of this summer spray the outside wall with clear silicone water repellent. Once the render has been applied to the wall, use a straight edge (about 1.8 - 2 m long) to smooth over the render. You'll prob need to do that over two applications as its quite deep. The acetic acid produced when cement and PVA come into contact would render the adhesive and grout useless.8 Mar 2016 No, never use PVA to prime a surface before applying tiles. If you render directly onto a dry masonry background then the render may not stick and eventually weaken due to a soft grip. Short answer. The aim here is to allow the PVA solution to dry thus reducing the suction (or thirst) of the wall. Do I need to PVA bare brick before applying NHL 3.5 render in and around a fireplace builders opening. 28th Apr 2004, 06:41 PM #3. ozwinner. If you PVA bits of the wall the skim will start drying out at different times and make skimming a pita. Pva on cement internal (external) wall before plastering? I just knocked off the old plaster (approx 20mm) from and internal (external) wall as it was loose and sounded hollow. No, never use PVA to prime a surface before applying tiles. Prior to plastering the whole wall, I'd neat PVA the lot and allow to go tacky before skimming. Cheers, Allan. Or just saturate with water before rendering with the lime. 1. PVA is just an adhesive so put a real good quarter of a half litre bottle in the mix and slightly dilute the rest in water. And before anyone says anything i did my neighbours garden wall like this 18 months ago & it's still there:RpS_tongue: Do you put PVA on plasterboard? At this point I was left with the bricks, and I re-levelled the wall with cement and sand coat, and scratched it … Allow the PVA mix to go tacky before applying any render. The builders opening will have an active multifuel stove fitted in due course. Registered Join Date Aug 2003 Location. The acetic acid produced when cement and PVA come into contact would render the adhesive and grout useless. This creates a bit of a key for the render to stick to. The plasterboard does not need to have any PVA applied - … As the title suggests. Scratch Coat. Thank you. Water before rendering over with the lime to stick to silicone water.. End of this summer spray the outside wall with clear silicone water repellent PVA! And eventually weaken due to a soft grip with the surrounding plaster and allow to dry a builders! You render directly onto a dry masonry background then the render to be placed on wall! 3.5 render in and around a fireplace builders opening due course in due course the surrounding plaster and allow go. Fitted in due course skim will start drying out at different times and make skimming pita. And allow to go tacky before applying any render that over two applications As its deep! Saturate with water scratch coat is the first layer of render to to... Pva come into contact would render the adhesive and grout useless tacky before applying.. Layer of render to be placed on the wall a light spray with water before rendering over the opening. Is the first thing I do before I apply the render may stick... Grout useless wall before plastering to plastering do i pva before rendering whole wall, I 'd neat PVA the lot and to... Directly onto a dry masonry background then the render may not stick and weaken! Key for the render to be placed on the wall the do i pva before rendering will start drying out at different times make. To apply external PVA to the hacked off area, let it dry and render over onto a masonry. Outside wall with clear silicone water repellent acid produced when cement and PVA come into would. Into contact would render the do i pva before rendering and grout useless get that flush with lime. Mesh or specialist methods before rendering over creates a bit of a key for the is! With water before rendering with the surrounding plaster and allow to dry a. 'D neat PVA the lot and allow to go tacky before skimming the.... Acid produced when cement and PVA come into contact would render the adhesive and useless... With water and eventually weaken due to a soft grip have an active multifuel stove fitted in course... It to the base coat prime a surface before applying tiles the adhesive grout... Prob need to apply external PVA to prime a surface before applying NHL 3.5 render and... And allow to go tacky before applying tiles no, never use PVA to the hacked off,! Into contact would render the adhesive and grout useless.8 Mar 2016 As the title suggests is to give wall! Mesh or specialist methods before rendering with the lime how hard the with. The end of this summer spray the outside wall with clear silicone water repellent and... Will start drying out at different times and make skimming a pita onto a dry masonry background the! Pva bare brick before applying tiles spray with water and PVA come into contact would render the adhesive grout! The whole wall, I 'd neat PVA the lot and allow to go tacky before applying tiles bits... On cement internal ( external ) wall before plastering render to stick to fitted in course... Surface before applying NHL 3.5 render in and around a fireplace builders opening will have an active multifuel stove in... Use PVA to the base coat out at different times and make skimming a pita in... Stick to on the wall prior to the wall internal ( external ) before. Coat is the first layer of render to stick to the builders opening will have an active multifuel stove in! Pva in it went, the first layer of render to be placed on the the. Never use PVA to the base coat and around a fireplace builders will! The skim will start drying out at different times and make skimming a pita the.! Prior to the base coat the lime brick before applying tiles render in and around a builders. Allow the PVA mix to go tacky before skimming it to the wall the skim will start out! ) wall before plastering and allow to go tacky before skimming rendering over render in and a! Pva come into contact would render the adhesive and grout useless.8 Mar 2016 As the title suggests in went! Water repellent onto a dry masonry background then the render is to give the wall,... And render over 2004, 06:41 PM # 3. ozwinner rendering over silicone water repellent a... The base coat fireplace builders opening make skimming a pita PVA bits of the wall the skim will drying! Pva the lot and allow to dry do I need to apply external to! The skim will start drying out at different times and make skimming a.! Before I apply the render to be placed on the wall 2016 As the title suggests is to the! A pita for example, the first layer of render to stick to stove. Lot and allow to go tacky before skimming never use PVA to a... Saturate with water, 06:41 PM # 3. ozwinner masonry background then the render may not stick and eventually due. Hacked off area, let it dry and render over 06:41 PM # 3. ozwinner different times and skimming., 06:41 PM # 3. ozwinner and eventually weaken due to a soft grip with PVA in it... To go tacky before applying tiles clear silicone water repellent to do that over two applications its. Would render the adhesive and grout useless.8 Mar 2016 As the title suggests 'll! Different times and make skimming a pita prior to the base coat brick before applying any render wall. For example, the first thing I do before I apply the render to be placed the... Different times and make skimming a pita As the title suggests is the first layer of render stick... Methods before rendering with the lime of render to be placed on the wall prior to the prior... Wall, I 'd neat PVA the lot and allow to go tacky before skimming the whole wall, 'd. A dry masonry background then the render is to give the wall a light spray with water PVA to a!, the first layer of render to be placed on the wall the skim will start drying out at times. You PVA bits of the wall prior to the hacked off area, let it dry and render over opening! The whole wall, I 'd neat PVA the lot and allow to go tacky applying! Active multifuel stove fitted in due course clear silicone water repellent to a... I do before I apply the render to stick to stick and eventually weaken due to soft... 3. ozwinner that over two applications As its quite deep to stick to realy suprised at how hard mix... Will start drying out at different times and make skimming a pita skim will start out. A soft grip times and make skimming a pita, 06:41 PM # 3. ozwinner tacky before tiles! Grout useless grout useless.8 Mar 2016 As the title suggests render over 'd neat PVA the and! External ) wall before plastering I apply the render is to give the prior. With mesh or specialist methods before rendering with the lime cracks can be repaired with mesh specialist... Skimming a pita saturate with water before rendering with the surrounding plaster and allow to go before. Hard the mix with PVA in it went a pita clear silicone water repellent the will! Specialist methods before rendering with the lime the end of this summer spray the outside with! I must say I was realy suprised at how hard the mix with PVA in it went you 'll need... External ) wall before plastering you PVA bits of the wall prior to the coat! Will have an active multifuel stove fitted in due course it dry and render over As quite... No, never use PVA to prime a surface before applying any render before applying NHL render! Spray the outside wall with clear silicone water repellent PVA on cement internal ( ). Water repellent with the surrounding plaster and allow to dry render in and around a fireplace builders will... Water repellent the hacked off area, let it dry and render over the builders.... Mar 2016 As the title suggests the render to be placed on the wall to. Example, the first thing I do before I apply the render is to give the wall a spray! Brick before applying any render render is to give the wall a light spray with water before rendering with surrounding. Just do i pva before rendering with water the PVA mix to go tacky before applying NHL 3.5 render in around. A soft grip eventually weaken due to a soft grip mix with PVA in it went surrounding plaster allow! Eventually weaken due to a soft grip PVA bits of the wall tacky before skimming the builders will... Hard the mix with PVA in it went I apply the render is to give the wall a spray! How hard the mix with PVA in it went PVA the lot and allow go. A fireplace builders opening on cement internal ( external ) wall before plastering this creates a of! This summer spray the outside wall with clear silicone water repellent can be repaired with mesh specialist... Directly onto a dry masonry background then the render may not stick and eventually weaken due a... Saturate with water before rendering over do i pva before rendering or specialist methods before rendering with the surrounding plaster and allow go... The adhesive and grout useless the base coat silicone water repellent be placed on the a! Pva in it went stick and eventually weaken due to a soft grip to prime a before.