Advise on gftk joint mortars product range

[luzippu]

Hi,

i have a 30sqm patio of 900x600 Indian Sandstone flags that i have laid 2 years ago.

I originally did the pointing with Weatherpoint 365, however almost half of it already needs retouching because it's coming off.

My patio is in a very shaded area and doesn't get much sun (even in the summer) so i have a frequent build up of algae which means i jet wash the patio twice a year to keep it clean and looking as new (bought the flags from London Stone and they look great!)

I have been looking around for a different product this time and have come across (as suggested on this website) the GftK range.

My plan is to remove the existing mortar using a mortar-raking blade and angle grinder and then re-apply a slurry resin based mortar more resistant to jet-washing.

My questions:

1. Is the vdw 840 Plus going to be the same as Weatherpoint 365 and come off after a few years of jet washing?
2. Should i then opt for the vwd 850?
3. What is the average working time for the vwd 850? As i understand you have to work quicker compared to the ready-mixed solutions (Weatherpoint 365 / vdw 840 Plus)
4. Finally, in your experience how long is it going to take to lift the old pointing based on 30sqm of 900x600 flags with a 5mm to 10mm gaps using an angle grinder and suitable blade/s?

Many thanks
Paul

[Azpects]

Hi,

i have a 30sqm patio of 900x600 Indian Sandstone flags that i have laid 2 years ago.

I originally did the pointing with Weatherpoint 365, however almost half of it already needs retouching because it's coming off.

My patio is in a very shaded area and doesn't get much sun (even in the summer) so i have a frequent build up of algae which means i jet wash the patio twice a year to keep it clean and looking as new (bought the flags from London Stone and they look great!)

I have been looking around for a different product this time and have come across (as suggested on this website) the GftK range.

My plan is to remove the existing mortar using a mortar-raking blade and angle grinder and then re-apply a slurry resin based mortar more resistant to jet-washing.

My questions:

1. Is the vdw 840 Plus going to be the same as Weatherpoint 365 and come off after a few years of jet washing?
2. Should i then opt for the vwd 850?
3. What is the average working time for the vwd 850? As i understand you have to work quicker compared to the ready-mixed solutions (Weatherpoint 365 / vdw 840 Plus)
4. Finally, in your experience how long is it going to take to lift the old pointing based on 30sqm of 900x600 flags with a 5mm to 10mm gaps using an angle grinder and suitable blade/s?

Many thanks
Paul

Hi Paul,

Based on what you've said it sounds like there maybe drainage issues with this site particularly if you're getting a regular build up of algae

Do you know what base the slabs were laid on?

[luzippu]

So to be more precise, there is a large corner area of the patio under trees. this is where i have the problem with the flags going green after a while and yes water drainage in that corner is not great, mainly because the garden is on a slight slope and on heavy rainfalls water collects and takes ages to try off.

And moreover because i did the work (as a non-professional) hence I am sure I could have done more with drainage. i can't remember exactly the measurements of hardcore and type one i used at the time but i tried to follow the guidelines on this website as much as i could. so please don't consider this a perfect job!

I also like to jet wash in the spring and at the end of the summer to clear away tree sap that builds up over the flags and along the joints.

Looking at your website I take EasyJoint could then be another contender?

thanks

[Azpects]

So to be more precise, there is a large corner area of the patio under trees. this is where i have the problem with the flags going green after a while and yes water drainage in that corner is not great, mainly because the garden is on a slight slope and on heavy rainfalls water collects and takes ages to try off.

And moreover because i did the work (as a non-professional) hence I am sure I could have done more with drainage. i can't remember exactly the measurements of hardcore and type one i used at the time but i tried to follow the guidelines on this website as much as i could. so please don't consider this a perfect job!

I also like to jet wash in the spring and at the end of the summer to clear away tree sap that builds up over the flags and along the joints.

Looking at your website I take EasyJoint could then be another contender?

thanks

We are certainly a contender

The reason I ask is because I wondered whether the compound had ever actually fully cured, if water can't get away the compound will fail. What can happen is the top goes hard but it remains soft underneath, hence why it is now coming out potentially.

If that is the case, re-installation of similar compound may lead to the same issue again

[luzippu]

ok, so looking at my old notes and sketches it looks like i had 75mm to 100mm of type 1 down on top of some hardcore (rubble from the previous paving + shed base) then if i remember rightly it must have been at least 50mm of 6:1 mix sand and cement.

perhaps not the deepest base i understand, but certainly nothing i can go alter now

the flags are all still attached solid apart from 2 in a corner which started to wobble last summer and i will be re-laying this weekend.

as mentioned the patio is in a slight slope leading towards aco drains and apart from the mentioned corner the rest seems to dry up fairly quickly after a downpour.

i thought i had 2 options:
a. re-point the patches where the joints have come apart (not ideal)
b. angle grinder out all of the old joints and re-do, hence my question around alternative slurry resin based products.

I found Wheatherpoint 365 really easy to apply hence was looking to a similar approach.

thanks

[msh paving]

weather point is washed in so the curing argument wont work, ive been using weatherpoint since it was launched never had any issues, pressure washing can damage the product if high pressure or a cutting head is used.
GftK is as great product and if cost allows that would be the first choice, i've used 850 in a town centre with street sweepers and washers still as good today as 5 years ago MSH

[luzippu]

so, after much reading i get that using EASYJoint (or similar pre-mixed polymerics) will do the job for a garden patio and would be the best option for a DIYer like me.

however IF i wanted to go down the 2-part products route (vwd 850 or vwd 800):
- do i need to invest in a professional paddle mixer tool or can i just use my corded makita drill with a small (but long enough) diy paint paddle mixer bit for example?
- as asked before what is the max working time for vwd 850/800? Is it 5 or 10 or 20 minutes? when i used Wheatherpoint it was easy to spread and you had plenty of time to re-touch it and clean it off the sandstone flags. i just want to make sure i won't end up ruining the patio in case i don't do the job quick enough... I will have a friend helping me with the hose and brush, but do you think it's doable for 2 non-experienced DIYers?
- what's best suited for a 30sqm 900x600 flags with a 10mm gap? vwd 850 or vwd 800?
- and finally would 2 x 25kg buckets be enough for the job? average gap depth is 25mm to 35mm.

many many thanks

[Azpects]

weather point is washed in so the curing argument wont work, ive been using weatherpoint since it was launched never had any issues, pressure washing can damage the product if high pressure or a cutting head is used.
GftK is as great product and if cost allows that would be the first choice, i've used 850 in a town centre with street sweepers and washers still as good today as 5 years ago MSH

It's washed in with water but water doesn't cure the product, that is air, hence the need for it to be dry and therefore having a free draining base

The water aids the products self compaction and workability, it also acts as a barrier between the slabs and oil within the product, the oil present will sit on top.

So the main benefits are the fact you don't have to get on your hands and knees, forcing it into the joints

It's fast, around 20 times faster than traditional mortar methods

And rain doesn't stop you finishing your job. (In heavy rain it can unsettle the joints slightly but these can be topped up and releveled)


That's partly why these type of products are becoming increasingly popular

[Azpects]

ok, so looking at my old notes and sketches it looks like i had 75mm to 100mm of type 1 down on top of some hardcore (rubble from the previous paving + shed base) then if i remember rightly it must have been at least 50mm of 6:1 mix sand and cement.

perhaps not the deepest base i understand, but certainly nothing i can go alter now

the flags are all still attached solid apart from 2 in a corner which started to wobble last summer and i will be re-laying this weekend.

as mentioned the patio is in a slight slope leading towards aco drains and apart from the mentioned corner the rest seems to dry up fairly quickly after a downpour.

i thought i had 2 options:
a. re-point the patches where the joints have come apart (not ideal)
b. angle grinder out all of the old joints and re-do, hence my question around alternative slurry resin based products.

I found Wheatherpoint 365 really easy to apply hence was looking to a similar approach.

thanks

Hi luzippu

We would recommend b. If the joints are coming out, something has gone wrong there, do they feel wet, are they crumbling?

A 6.1 mix should be permeable however the algae on top (algae thrives in wet conditions) and the joints coming loose suggest drainage issues around that tree area. As I say, the product uses water to aid the installation process but the joints do need air to cure, if the joints don't get dry they don't cure.

What's the soil underneath the base, are you in a high water table area?

EASYJoint is a great product but I wouldn't want you having the exact same issue in 2 years time

[luzippu]

Yes we are in a heavy clay soil area...

perhaps this year i have been too heavy handed with the pressure washer. i do have the rotary attachment, but before i use that i go around the joint grooves (where dirt and sap have built up throughout the months) with the oscillating nozzle. my washer is a 110bar so not extremely powerful...

where the joints have come loose, it has been in small and large bits rather than crumbling.

thanks

[Azpects]

Yes we are in a heavy clay soil area...

perhaps this year i have been too heavy handed with the pressure washer. i do have the rotary attachment, but before i use that i go around the joint grooves (where dirt and sap have built up throughout the months) with the oscillating nozzle. my washer is a 110bar so not extremely powerful...

where the joints have come loose, it has been in small and large bits rather than crumbling.

thanks

Ah okay, that maybe the issue for the damp areas if the water is sitting on top of the clay

The other areas are alright?

We do a product called EASY Algae Remover which continues working after application for up to 12 months
http://www.azpects.co.uk/products/easy-algae-remover.aspx

For pressure washing we'd recommend you leave it two months after EASYJoint application. EASYJoint takes around a month to reach it's full hardness

When you do pressure wash it, we recommend using a fan type spray head. This needs to be held at an angle of 45 - 60 degrees with the head no closer than 6 inches (150mm) from the paving surface.

[luzippu]

do you have any stockists for the EASY range in Essex/Herts or a recommended online retailer?

[Azpects]

do you have any stockists for the EASY range in Essex/Herts or a recommended online retailer?

We're pretty well covered for those areas

If you fill in our contact form with your postcode we can send over a list of your nearest stockists as well as online stockists

http://www.azpects.co.uk/end-user-enquiry.aspx

[luzippu]

done, thanks

[Azpects]

done, thanks

Okay kool, if you have any queries just give a call +44 (0)1473 760777