[Simon@ Clearview contractors]

Hi all, A couple of weeks ago I pressure washed a block paved yard, re-sanded it a week later after rain, then started to seal it around the edges before having to abandon the job due to rain.  I managed to finish the job earlier this week(a week in between starting, stopping, and finishing). 
when I did the edges, I used a garden sprayer, not good as the sealant melted the rubber seals, to complete the job I used a masonary roller and bucket.

Now yesterday I gets a call from the customer's son not ver happy that the block paving is in 2 different shades.

I havn't been back to the job yet as I don't want to stand there scratching my head not knowing how to remidy the situation.

Has anyone encountered these problems? and what will be the best course of action to fix the problem?

Thanks in anticipation of your replies

[Kev Martin]

Essentially as long as you used the same sealer you have done nothing wrong!  What you have done is used two different application methods which means the sealer has been applied unevenly.  A little bit like trying to paint a relief (Fresco) wallpaper with a brush then trying to use a roller.  In addition if the client can tell the difference you must be using a solvent based enhancing sealer.  Give me a call with the exact name of the sealer you used on 07770 598855 and I will talk you through correcting it.

Kev Martin
Marble Life Ltd

[Griffus]

Never even think about sealing if rain possible.

If you must spray then only use a sprayer with viton seals.

Ideally roller on. Minimum of two coats / applications. The 2nd applied at right angles to the first.

It appears that you've made a bit of a bodge up all round.

From your post it sounds like just one coat of sealer has been applied, and at different thicknesses. First step would be to apply another coat to the complete surface. Roll this on at right angles to the last lot you rollered on.

If you have already applied two or more coats then you could try a light misting of xylene over the dodgy areas. Again, viton seals essential.

One other point, if the surface wasn't bone dry when sanding the sand will drop when it does eventually dry, this could undermine the integrity of the surface. Also, if sealing a surface that isn't 100% dry you'll have sealed moisture in the block and this will show a discoloration in no time.

Rather you than me.

Good luck

[Blast Away]

You've not melted the seals. You've probably not cleaned the sprayer through with xylene and the lines are now solid.

And I think you mean 'blooming' as when you've abandoned the job the sealant has got wet and now left with a silver film(blooming) where moisture is trapped mixed in with the sealant. This can be sorted with xylene.

[Kev Martin]

Never even think about sealing if rain possible.

If you must spray then only use a sprayer with viton seals.

Ideally roller on. Minimum of two coats / applications. The 2nd applied at right angles to the first.

It appears that you've made a bit of a bodge up all round.

From your post it sounds like just one coat of sealer has been applied, and at different thicknesses. First step would be to apply another coat to the complete surface. Roll this on at right angles to the last lot you rollered on.

If you have already applied two or more coats then you could try a light misting of xylene over the dodgy areas. Again, viton seals essential.

One other point, if the surface wasn't bone dry when sanding the sand will drop when it does eventually dry, this could undermine the integrity of the surface. Also, if sealing a surface that isn't 100% dry you'll have sealed moisture in the block and this will show a discoloration in no time.

Rather you than me.

Good luck

[Kev Martin]

I am not sure what either of the last two posts are about! Neither have obviously never heard of MVT water based sealers

Kevin Martin
Marble Life Ltd

[BDCS]

What is a MVT water based sealer ? I've never heard of them either but would like to know more please. If the sealer used was polyeurethane then its an abraid job, if its acrylic then roller the whole job with xylene.

[BDCS]

Found it - "moisture vapour transmission"  but still need to know more ! The sealer I found was water based but not suitable for drives. garage floors or heavy foot traffic

[Blast Away]

I am not sure what either of the last two posts are about! Neither have obviously never heard of MVT water based sealers

Kevin Martin
Marble Life Ltd

I'm not sure what your post is about. He's not used that type of sealant. But oooh get you it's so obvious.

[Kev Martin]

Firstly I have offered no advice!  The reason for this is I do not know what type or make of sealer was used!  I have only made an assumption based on the finished result and I am waiting for a reply posted on here or a telephone call.  Many modern penetrating sealers are Moisture Vapour Transmissable or Breathable if you like!
This means whether they be water or solvent based it is only necessary to have the surface dry and not the sub surface when applying the sealer because the water still contained in the stone can still evaporate.  However, this said in the main the sealers I have mentioned do not change the appearance of the stone unless they are enhancing penetrating sealers.  However even several of these are MVT so hence the reason for asking exactly which one was used prior to offering advice.

Kev Martin
Marble Life Ltd
 

[Griffus]

Kevin, have you amended your initial reply? It seems different from how I read it yesterday It also now contradicts your second post.

1 - "In addition if the client can tell the difference you must be using a solvent based enhancing sealer"
2 - "I am not sure what either of the last two posts are about! Neither have obviously never heard of MVT water based sealers"


I thought it was pretty obvious that the guy was referring to a solvent based sealer.............


"I used a garden sprayer, not good as the sealant melted the rubber seals"


.......................which is why the posts that followed did.




"I am not sure what either of the last two posts are about!"

Your lack of comprehension is strange considering your documented experience.


I have to admit to not having heard of MVT sealers. I'll take a look but I have to admit I thought acrylic, poly's or maybe even keybond were the only viable options for block paving.

[Kev Martin]

Kevin, have you amended your initial reply? It seems different from how I read it yesterday It also now contradicts your second post.

1 - "In addition if the client can tell the difference you must be using a solvent based enhancing sealer"
2 - "I am not sure what either of the last two posts are about! Neither have obviously never heard of MVT water based sealers"


I thought it was pretty obvious that the guy was referring to a solvent based sealer.............


"I used a garden sprayer, not good as the sealant melted the rubber seals"


.......................which is why the posts that followed did.




"I am not sure what either of the last two posts are about!"

Your lack of comprehension is strange considering your documented experience.


I have to admit to not having heard of MVT sealers. I'll take a look but I have to admit I thought acrylic, poly's or maybe even keybond were the only viable options for block paving.

Ian

I haven't altered any posts and have only made an assumption on what he has used.  I cannot also see where i contradict myself! That said the assumption should have read enhancing sealer.  it doesn't look like he is interested anyway because as yet there is no response.  With response to whats available it is difficult to keep up to date sealers are being continuously improved.

Kev Martin
Tiling Logistics
Marble Life ltd

[Matt Gibson]

ive always thought that the acrylic sealers (surface sealer, that actually form a surface coating over the paving) were NOT breathable, hence if you use them with even the slightest bit of moisture in the stone, you will get blooming..

Whereas if you use a penetrating sealer (water based or solvent based as long as it doesnt affect the look of the surface or leave a surface coating) then you can seal with the stone still damp (but the surface dry) and the moisture can still escape as thereis no seal on the surface stopping it.

Just what ive always thought..

[drive surgeon]

dont seal 

[Kev Martin]

ive always thought that the acrylic sealers (surface sealer, that actually form a surface coating over the paving) were NOT breathable, hence if you use them with even the slightest bit of moisture in the stone, you will get blooming..

Whereas if you use a penetrating sealer (water based or solvent based as long as it doesnt affect the look of the surface or leave a surface coating) then you can seal with the stone still damp (but the surface dry) and the moisture can still escape as thereis no seal on the surface stopping it.

Just what ive always thought..

Absolutely spot on regarding the penetrating sealers.  With regards to the topical sealers you are in the main correct unless the topical sealer is also breathable (MVT) but if not you will tend to get blooming below and it usually fails

Kev Martin
Marble Life Ltd