I want to fill gaps between my patio paving flags.?

I've just jet washed my patio and paving slabs in my back garden and now where they meet there is a gap. I've bought some ready mixed concrete and have been told to brush it in? Is it really that simple?
Do not use concrete use a sand and cement mix about 3:1 should do and brush it in the joints in a dry mix . When completed get a jointing iron or a bit of old copper pipe about 4" long and an inch around, get the mix slightly wet and rub the pipe along the joint to make a nice finish
It is that simple but I would not use concrete, I would just use sand because if at any time you want to remove those pavers or do something else to that spot it is going to be a pain to get rid of the pavers.

Just use sand.
yes it is,also you can use plain sand,or stone dust.just brush or sweep between the pavers.you may have to do again after it settles.ground cover planted between also works.i have a friend that planted lemon thyme between his.it doesnt mind being stepped on and when you do it releases a lemon fragrance.good luck
Yes! Brush in dry, either wait till it takes up moister from ground or very light spray from hose, or you will just wash it away, Try last thing at night this way you can rely on the dew!
If it had mortar to begin with I would use mortar not concrete. concrete has rocks in it. some pavers use a coarse sand rather than mortar between the pavers.
How big is the gap ? if it is 3 inches or wider perhaps it would be a good idea to fill in the gap with crushed stone ? Landscapers do this quite often. remember if the gap isn't wide enough this will not work.
yes and no, don't use raw cement or even a pre mixed sand cement product, the best solution is coarse sand sometimes called river sand. Just brush this into the paving with a stiff bristle broom. By using sand there is no expansion problem or cracking. Cement filler (grout) is only used if the pavers are laid on a concrete slab base.
Yes it is ,as long as you wet it with a watering can after wards. be carefull not to wash it out ' ronpad
stop and do not doanything listed above. What you want to use is marble dust. brush it into the joints and lightly mist with a water hose until it's completely wet.

or use sand. brush the sand into the joints and spray with Prosoco's PK sand joint stablizer or similar product
bizowner said marble dust and i'll tell you why.
If you use sand then you will have grass, weeds etc growing between your stones in no time. An unsightly mess.
If you use the ready mix concrete you may have huge mess to deal with AND don't forget how it expands and contracts so using it in between the stones could over time cause them to buckle up resulting in an uneven surface.
While the marble dust is easy to use - just pour out a pile onto the stones and sweep them in between, sweep off the stones as much as possible and lightly dampen the dust. Don't wash it away!
it hardens and seals and lasts and won't damage your stones.
you can use slag sand, of unilock has a mixer you can use, it depends on how big is the gap.
Happy is right, sand is good but it lets grass and weeds grow in the sand; however, I started some moss cuttings in the sand between by paving stones, and it took right off and looks good in the flower garden I have. I don't mind that everything isn't flat and even in this area.