i use reisser screws when instaling decking, gold heads
I wouldn't use visible screw fixing with Ipe, it is so stable you can get really tight spacing so that concealed fixing looks great. I first used EB-TY hidden fasteners on an Ipe deck three years ago and have had no problems since. They give a very neat finish (see below) and ensure regular and very tight spacing (Ipe doesn't expand much and so can be laid very close).
EB-TY are plastic biscuits with a spacer bar in the middle and a hole for the screw. They cannot "pop" because the screw goes through the spacer and through the edge of the board.
As for the cost, given the price of Ipe the price of the EB-TY is not significant. The real cost you need to build in is for the additional labour: that is significant. You will need to use a biscuit cutter over each joist so that to join two 15' boards over 18" joists involves making 20 cuts with the jointer. Then you need to pre-drill each screw hole. The first and last run of decking will need to be fixed through the face with counter-bored holed filled with Ipe plugs. On top of the fun with board thickness variation and the need to end-treat all cuts, laying Ipe with concealed screws adds a lot of labour to a job.
Two notes of caution.
First the Swanson stainless steel screws which come with the EB-TY are terrible. They have a No.1 square-drive socket which rounds out too easily leaving a screw half in to an Ipe board which grips like set concrete. We throw the screws away and buy Carpenter's Mate SS Finish Screws which have a No. 2 socket and have never given any trouble. But that is more expense!
Second, remember to clean your biscuit cutter every day. Ipe produces an incredibly fine yellow dust which gums up everything and will kill the tool if it gets rained on. Ipe dust turns into a red liquid when wet, it stains everything and then it sets into rock hard resin when dry: time for a new biscuit cutter!
Perhaps gold head screws through the face aren't such a bad idea after all.
Take a look at the kreg hidden fixing system when you next install a deck. The jig is around £100 but that's a one off cost then it's just the cost of the special screws. The system fixes through the side of the board from top down. Very simple and works well on soft wood also. In my opinion all smooth faced decking needs a hidden fixing.
It's actually pretty quick once you get used to it. In a perfect world you should have 2 jigs with one guy pre drilling and one guy screwing. but we just use 2 drills, one with the drill and one with the driver. It's a simple system and gives a decent finish without much messing around. I would say it's similar time to install compared with countersinking and screwing and around double the time if you just screw straight.
The deck is balua, the picture was untreated, it looks fantastic once oiled.
Funny that, just a couple of hours ago I was googeling a router jig to cut curves and saw the Krug hidden screw jig. Looks pretty time consuming, then I guess all the hidden fixing systems are pretty labour intensive eh?
Beautiful deck- IPE?