Self levelling compound - sanding down?
Discussion
I laid some Sika self levellign compund a few weeks ago.
Unfortunatley where the front door is, it is a bit too high so with the carpet it is rubbing too much and does not allow for a mat.
I just need to reduce the height by about 5mm (I did put it on quite think) - to create a slope udner the door.
Can this stuff be manually sanded down or is there another way? I want to avoid breaking it out.
Unfortunatley where the front door is, it is a bit too high so with the carpet it is rubbing too much and does not allow for a mat.
I just need to reduce the height by about 5mm (I did put it on quite think) - to create a slope udner the door.
Can this stuff be manually sanded down or is there another way? I want to avoid breaking it out.
I have used one of these and it works very well / fast.
http://www.toolstation.com/shop/Power+Tool+Accesso...
Obviously there is a lot of dust and keep it moving !
http://www.toolstation.com/shop/Power+Tool+Accesso...
Obviously there is a lot of dust and keep it moving !
Hi,
Similar to the op
Laid some self levelling compound but it seems to have been a dud batch; lots of high spots and drops throughout.
I have laid self levelling compound many times without issue, this is the first time the finish has been poor.
I know it was made with the correct ratio of water so no idea why it’s gone wrong this time as it gives the appearance in places it’s been brushed.
My question is
Is sanding down with a angle grinder using a Diamond Concrete Grinding Disc still the best option?
Need to remove about 1-2mm in places.
Similar to the op
Laid some self levelling compound but it seems to have been a dud batch; lots of high spots and drops throughout.
I have laid self levelling compound many times without issue, this is the first time the finish has been poor.
I know it was made with the correct ratio of water so no idea why it’s gone wrong this time as it gives the appearance in places it’s been brushed.
My question is
Is sanding down with a angle grinder using a Diamond Concrete Grinding Disc still the best option?
Need to remove about 1-2mm in places.
ACCYSTAN said:
Hi,
Similar to the op
Laid some self levelling compound but it seems to have been a dud batch; lots of high spots and drops throughout.
I have laid self levelling compound many times without issue, this is the first time the finish has been poor.
I know it was made with the correct ratio of water so no idea why it’s gone wrong this time as it gives the appearance in places it’s been brushed.
My question is
Is sanding down with a angle grinder using a Diamond Concrete Grinding Disc still the best option?
Need to remove about 1-2mm in places.
Sounds like it has got damp at some point and not mixed smoothly. You can normally scrape the surface down with a bladed scraper, it is easier and quicker than trying to use power tools. Once it is flat just seal the areas that you have removed material from.Similar to the op
Laid some self levelling compound but it seems to have been a dud batch; lots of high spots and drops throughout.
I have laid self levelling compound many times without issue, this is the first time the finish has been poor.
I know it was made with the correct ratio of water so no idea why it’s gone wrong this time as it gives the appearance in places it’s been brushed.
My question is
Is sanding down with a angle grinder using a Diamond Concrete Grinding Disc still the best option?
Need to remove about 1-2mm in places.
Thank you for the replies
It’s a decent size room. A bladder scrapper would take a lot of effort but thanks for suggestion.
I might as well buy the bullet and get the diamond grinding disc, hopefully it will last a good while and I can use it on a future project.
I did try an orbital sander with 40 rated paper but ii went through 5 sheets fast before I gave up, just not strong enough although it did work.
Would take 400 odd sheets at that rate!
It’s a decent size room. A bladder scrapper would take a lot of effort but thanks for suggestion.
I might as well buy the bullet and get the diamond grinding disc, hopefully it will last a good while and I can use it on a future project.
I did try an orbital sander with 40 rated paper but ii went through 5 sheets fast before I gave up, just not strong enough although it did work.
Would take 400 odd sheets at that rate!
I'm going to be a contrarian here...
(Self-) Levelling compound is designed to have a high compression strength, but very little fracture strength. You'll see what I mean if you have a loose piece, where you can snap it with your hands.
If you use a high powered tool to sand it down, you will most likely cause mini-fractures, and compromise the compression strength / adhesion to the substrate.
I would (and have recently done, last Friday), sand it manually, with a rubbing block (20 grit) like this https://www.screwfix.com/p/marshalltown-20-grit-ru...
Use a straight edge to check your levels, and this should take 20 minutes max. This will be quicker and easier on the floor than the time it takes to setup, and clean up using an electric tool.
Always wear a mask and eye protection when exposing yourself to sanded and/or raw cement dust.
(Self-) Levelling compound is designed to have a high compression strength, but very little fracture strength. You'll see what I mean if you have a loose piece, where you can snap it with your hands.
If you use a high powered tool to sand it down, you will most likely cause mini-fractures, and compromise the compression strength / adhesion to the substrate.
I would (and have recently done, last Friday), sand it manually, with a rubbing block (20 grit) like this https://www.screwfix.com/p/marshalltown-20-grit-ru...
Use a straight edge to check your levels, and this should take 20 minutes max. This will be quicker and easier on the floor than the time it takes to setup, and clean up using an electric tool.
Always wear a mask and eye protection when exposing yourself to sanded and/or raw cement dust.
Semmelweiss said:
I'm going to be a contrarian here...
(Self-) Levelling compound is designed to have a high compression strength, but very little fracture strength. You'll see what I mean if you have a loose piece, where you can snap it with your hands.
If you use a high powered tool to sand it down, you will most likely cause mini-fractures, and compromise the compression strength / adhesion to the substrate.
I would (and have recently done, last Friday), sand it manually, with a rubbing block (20 grit) like this https://www.screwfix.com/p/marshalltown-20-grit-ru...
Use a straight edge to check your levels, and this should take 20 minutes max. This will be quicker and easier on the floor than the time it takes to setup, and clean up using an electric tool.
Always wear a mask and eye protection when exposing yourself to sanded and/or raw cement dust.
I tried with a belt sander and it wore out the belts so fast it wasn't worth it - they sell diamond discs for a reason(Self-) Levelling compound is designed to have a high compression strength, but very little fracture strength. You'll see what I mean if you have a loose piece, where you can snap it with your hands.
If you use a high powered tool to sand it down, you will most likely cause mini-fractures, and compromise the compression strength / adhesion to the substrate.
I would (and have recently done, last Friday), sand it manually, with a rubbing block (20 grit) like this https://www.screwfix.com/p/marshalltown-20-grit-ru...
Use a straight edge to check your levels, and this should take 20 minutes max. This will be quicker and easier on the floor than the time it takes to setup, and clean up using an electric tool.
Always wear a mask and eye protection when exposing yourself to sanded and/or raw cement dust.
As you're putting zero pressure on it, just removing the surface I can't see how it can affect anything and my hall floor has been done and used as a wearing surface for 3+ years as I haven't got around to covering it yet !
As it can open up the surface I brushed a bit of watered down SBR on to seal it
KTMsm said:
I tried with a belt sander and it wore out the belts so fast it wasn't worth it - they sell diamond discs for a reason
As you're putting zero pressure on it, just removing the surface I can't see how it can affect anything and my hall floor has been done and used as a wearing surface for 3+ years as I haven't got around to covering it yet !
As it can open up the surface I brushed a bit of watered down SBR on to seal it
Different folks, different strokes... This is what makes the world so interesting.As you're putting zero pressure on it, just removing the surface I can't see how it can affect anything and my hall floor has been done and used as a wearing surface for 3+ years as I haven't got around to covering it yet !
As it can open up the surface I brushed a bit of watered down SBR on to seal it
moustachebandit said:
Never come across one of thoseHave you used one ?
Presumably it's like a harder pumice stone and just gradually wears down
V8RX7 said:
I have used one of these and it works very well / fast.
http://www.toolstation.com/shop/Power+Tool+Accesso...
Obviously there is a lot of dust and keep it moving !
Would you wet the concrete when using 1 of these.http://www.toolstation.com/shop/Power+Tool+Accesso...
Obviously there is a lot of dust and keep it moving !
KTMsm said:
Never come across one of those
Have you used one ?
Presumably it's like a harder pumice stone and just gradually wears down
Have you used one ?
Presumably it's like a harder pumice stone and just gradually wears down
Yes they are similar to a pumice stone, I have used them in the past to level/remove soft layers of concrete. Unfortunately because of what I was doing, I had to use them dry. So dust masks and goggles (at least) are a must.
Some of the guys who use them for defect repairs treat them a bit like wet and dry sandpaper, cuts down the dust, and "rinsing" the block in water helps prevent clogging.
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