Dear Sir,
Pls find below answers of your queries,
1. There are only two types. Thick and Thin Only.
Test method is , Thick will fall down to earth when you will sprinkle it from height of 5ft and thin will disperse into environment.
Always try to use thick sand as it gives good binding between cement and bricks. But when the construction is in progress , might be thick not available when required so you have to use thin, because construction activity can be delayed in most of cases or you have to pay extra labour cost. Different names are being used as per sand availability in different areas e.g
-In Fsd Sand famous source is named as Chiniot Sand
-In Lhr Sand famous source is named as Ravi Sand
-In ISB, Sand famous source is named as Lawrencepur Sand
All these are commercial marketing tricks invented by Thakadaars 
and have nothing to do with types/ qualities. As sand is naturally occurring material so when machines are digging out sand near river TUKK (or kinaara you can say), thin and thick both sand come and dispatched to end users. You only can advise supplier to bring thick sand from the TUKK when thick sand begins from tukk. Thick sand will give you good finish of plaster on walls.
2. Sand can not be measured on trolley as it have un-even surfaces. You will always get trolley on lump sum rate and it may varied from areas to areas. Sand only can be measured when sand delivery is made on dumper or on an mazda car. You measure all three dimensions (length, width and height) and can do the payment according to quantity. For taking measurement of height/depth of dumper or mazda or shehzoor, they shall have a long iron bar with them, you can measure then its size. There are no 2 vol options, there is only 1 option that is multiply all 3 dimensions simply and pay the amount.
for Example
Dumper Sand Retaining Area Length = 15 ft
Dumper Sand Retaining Area Width = 8 ft
Dumper Sand Retaining Area Height = 8 ft
Total Sand in Cu Ft = 15*8*8 = 960 Cu ft
Sand Ratios Avg Basis:
Wall Construction 6, 1 (6 Part Sand , 1 part Cement)
Plaster (4,1 or 3,1)
Roof Lanter Day 1,2,4 (Cement, Sand, Bajri)
3. We dont have a running site in Lhr. You can make meeting plan in ISB subject to 1 week prior advance information. I will confirm you as per my availability. For this, inbox me private message.
I hope above fulfills your requirement. Let me know if you require any further info.
Thanks.
