Your best bet is probably to pour boiling water on the weeds.
The heat will kill the plants, and the water will of course be harmless to the birds as soon as it cools.
Just be careful not to burn yourself!
gardening.stackexchange.com/users/1447/michelle
They make tools for just this purpose with the slightly-rude sounding name of "Crack Weeder".
They are either a very narrow hoe / knife, or a metal-bristled brush.
Using one of these is less tedious than hands-and-knees pulling of the little weeds.
For expensive and high quality tools see http://www.leevalley.com/en/garden/page.aspx?cat=2,2300&p=33275 - no affiliation except they have a lot of my money and have always given good service - where you can see that some people prefer a 6" handle and they get down to the ground, while others like a long handle like a hoe.
I am sure you could find similar things in your local hardware and gardening store.
gardening.stackexchange.com/users/754/Kate Gregory
If you want a viable low maintenance solution you should consider removing the bricks/tiles and replacing any soil with underneath or in between the bricks/tiles with crushed rock.
You can usually buy it cheap in quantity if you have a quarry nearby.
If you don't want to dissemble the patio you can try to scrape out as much dirt as you can from between the cracks and fill them with finely ground stone.
Make sure to use a breathing protection when handling it.
You can use an old chisel or a flathead screwdriver for this.
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I have a propane weed torch that I use to burn the weeds in cement cracks.
I got mine from a gardening supply store, but they are on Amazon.
I can't use it near the house or the porch screen (plastic screen), but it works pretty good on driveways and cracks.
You may have to revisit the weed area about every month or so.
Just be sure to inspect all of the fittings for leaks when you attach it to a propane tank and every time before use.
The one I have is a little cumbersome to carry around
and I wish the hose was a little longer, but you could put it in a wheel barrow or wagon and move it around the yard.
I cannot open the propane valve all the way.
If I do open the tank valve all the way and try to use the squeeze valve on the handle the pressure will sometimes put out the flame.
It may just be the one I purchased.
I've only had it for about 2 years but it works.
It just isn't fun to do in the middle of the day in the heat and humidity.
The burnt weed/plant may discolor the tile/bricks black.
gardening.stackexchange.com/users/14587/Charles Byrne
Depending on how much time you want to sacrifice, you can also plant something in the cracks which will shade the weeds and make garden look nicer, here are some examples: http://www.theguardian.com/lifeandstyle/2013/jul/26/gardens-plants-cracks-paths
gardening.stackexchange.com/users/14889/Rafs Kitchen Garden on Youtube
Here in the UK we have many garden birds that feed from the small cracks in our brick-paved patio. Unfortunately, those small cracks are also full of various weeds and grass at the moment.  What is the best way of killing it all, but without poisoning the birds that eat from the ground?    I appreciate it can be weeded meticulously by hand, but I feel that way lies madness...!
Bird-friendly weedkiller for patio?
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<weed-control><birds>
gardening.stackexchange.com/questions/25028
gardening.stackexchange.com/users/14803/Codemonkey
You could pour boiling water into the cracks or use a propane torch. There are tools that are made for this kind if weeding. One easy way is to pour boiling water on the weeds or there is a tool for this purpose called a "Crack Weeder". A viable low maintenance solution would be to remove the bricks/tiles and replacing any soil underneath or in between the bricks/tiles with crushed rock or alternately you can use apropane weed torch to burn the weeds in cement cracks.  
One easy way is to pour boiling water on the weeds. There is a tool for this purpose called a "Crack Weeder". A viable low maintenance solution would be to remove the bricks/tiles and replacing any soil underneath or in between the bricks/tiles with crushed rock. You can use apropane weed torch to burn the weeds in cement cracks.  