I need to replace my deck shortly.  I'm going to go with some sort of composite material.  Haven't decided yet on that.  I don't have a SCMS as of the moment and I will need one in order to trim the boards at a 45 deg angle.  Here is my issue.  I could spend the $1300 for the Kapex but considering I now have the Hammer K3 slider which makes it pretty easy to miter anything, I don't see where the Kapex would do much other than collect dust (pardon the pun) after being used for the deck project.  I'm a hobbyest so not running trim or crown and don't really plan to.  Is the Kapex overkill?  Would I be better off getting a $500 Makita or something else and saving the difference to get a Domino for other projects?  I'm obviously sold on Festool as we all are but I wanted to hear some other learned opinions. 

In my opinion it would depend on how you will use it in future projects.  If all you are going to do is trim one deck, then most any miter saw would work and being outside, DC may not be that big of an issue.  If you plan on using it in the shop to break down boards and make other cuts, then it might be worth the investment.  Having a slider negates the need for most things, but if you have set-ups on your slider and need to make a quick trim cut, then it might be good to hae an SCMS at your disposal.  I would probably opt for a Domino over the Kapex, though, as the Domino is a game changer for joinery and it would complement the tools you have. 

Scot 

I think Dan is right about using a TS55/75 saw.  Like he said make a jig (or use the MFT) for the cuts against the house and just run the ends long and trim them all off when done. 

As Brice suggested, you would be better off with the MFT.  Then you have something you will get a lot more use out of.  It's amazing the amount of uses you find for the MFT.

My take would be how much time - as a hobbiest - you would want to spend taking the material to the saw placement (shop versus deck area) and depending on the design of the deck ( diagonal / picture frame / combination / none of the previous) that you are trying to achieve.

I don't have a sliding table saw ( but wish I had yours   ) so I can't comment on the ease of potentially mitering 12' floppy boards - goes back to design possibilities - but my guess is that is not what is the best use of you sliding attachment or it's strongest points.  My guess might be entirely off base.

Going to the Kapex versus other saws issue.  In all honesty, prior to getting a Kapex I made a lot of money doing decks with other brand saws that cost less than the Kapex.  I love my Kapex and the accuracy that it provides and mine gets used to cut every type of material that I commonly run across, but for what your needs are at the current moment you could test ride the Kapex and decide within thirty days or you could purchase another brand, use it, and then sell it if it did not fit into your tool arsenal in the manner that anticipated your future needs.

Just my 2 cents.

Peter

turned out great warner. did you lay out the deck size knowing exactly how long each square needed to be from corner to corner? or did you layout best you could on a fixed deck size?

Well, I wouldn't go out and buy a MFT just to build a deck (and frankly, I don't know who would).  I'm assuming Howard has a TS55 and MFT already so using what he has is a better option than buying anything new.  Beside, for one deck cutting the decking on the MFT wouldn't be all that bad, trying to make a living that wouldn't work.

As for dust collection for decking, he mentioned using a composite.  I always use the vac when cutting that stuff because the big piles you'll leave in the yard aren't going to decompose like wood dust will.

Correct, Brice.  I have the TS 75 and MFT 1080 (it's listed in my signature) I'm going to run my boards along the diagonal like shown above but the diagonal will go from the house out to the edge where I will have a perimeter board going all the way around and the 45's will butt up against the perimeter board.  I built the original frame to accomodate that.  I originally used treated pine and it simply didn't hold up.  I don't think I will have any issue with the existing framework.  I suppose I could also rent a SCMS for the few days I would need it.  I also thought about using my MFT and TS75 but I think it would be a pain to try to make a lot of 45's.  I plan on using 12' boards unless it would be better to get 16's so I won't have as many joints.  I would have to alternate a bit to keep the joints from lining up with each other.  I guess it's like anything else, once you buy the Kapex, you find many other uses for it that you may have not thought of.  The comment from Brice about the dust collection in the yard is something I didn't consider and I believe you are spot on with that comment.  It's bad enough with regular wood chips, I can only imagine what's it's like with composite.  My dust deputy would handle that with the CT very easily.   As far as the Hammer goes, it was never in the equation for the deck.  Safety and accuracy is never overkill, IMO.  I don't want to go down that road again in an earlier thread but if you have never tried a slider, once you do, you would never go back.  It's simply that much better, especially when working with sheet goods.  I recently added their eccentric clamp and it allows me to keep my hands at least a foot away from the blade.  Even my wife is impressed with it.  She appreciates the safety and accuracy of Festool as well, she has never said a peep about a single Festool purchase I have made.  I'm very lucky!  

 A Kapex makes a great deck building tool, mine has been eating PT SYP and Redwood for the last two weeks without complaint.  The idea of buying one for a deck project is pretty silly though.  The only cuts you really want the capacity of a slider are for mitering your rim joist, but do you really want to lug a big SYP 2x10 onto your saw stand when you can get perfectly acceptable results with your skilsaw and a carpenters square?  Hopefully all your framing is covered with a nice skirting, and even a perfect miter is most likely going to open up before you finish the deck.

For laying the field of your deck you are much better to run the boards long, snap a line and cut them all with a skilsaw or track saw.  For your picture frame ( if you do one) you do want evenly spaced (not tight) miters, but that can be done with your skill saw or track saw after the boards are secure.  Basically cutting a kerf to get your spacing.  Having a miter saw is nice for your guard rail cap, you want to try to get those miters tight and they are not likely going to be 90's, also useful for your returns on your handrail if you have one.

So a nice used Makita or Dewalt 10" or 12" Compound miter saw will be able to easily do all of the tasks you need for a nice deck.  You can set it up on a sawhorse stand and leave it in the backyard for the Summer under a tarp and not worry about it.  Then you can keep it in the backyard and use it to cut up scrap wood and branches or sell it when you are done.

As for your decking choices.  If you have to rebuild the structure of your deck you are likely to spend over a Domino XL just on concrete, framing lumber, and metal.  Really do your homework before you buy into the "composite is maintenance free, and green" camp as it is a load of you know what.  What you end up with is a product that can never be refinished and will not biodegrade and most will look pretty lousy in 10 years.  As a woodworker, don't ignore your roots.  SA hardwoods, Redwood, Cedar, TM wood, and even PT SYP at least have the benefit of being able to be made beautiful again, and again. If built properly they can easily give you 30 years of service, can you say the same about composite?

How about ...

"the world will end if you don't buy a KAPEX"

... there. Now it's fully justified

I think those that said get the saw, build the deck then return it should be ashamed of yourself  . Nuff said !

If you are not planning to do any other work like trim,crown,...etc    Then yes it is overkill.You can get good result with most saws out there.Makita,Bosch,Dewalt,will do just fine.
I wouldn't worry about dust.It's just a matter of cleaning after the job is done.
There's no question that the Kapex is a good saw,but you're not going to benefit from it if you don't use it much.

i believe i said get the saw ,build the deck, see if you have any other use for it then return it. implying take advantage of the festool trial offer as thats what it's there for.

The Festool policy here in NA is to allow a user thirty days to use a tool in real life.  Within those thirty days the user has the right to return with no questions asked a used tool for a replacement or refund.  Freight is a cost to the user.  Accessories purchased for the tool do not fall under that policy although dealers may have separate more generous policies.

Festool established the policy and of course could alter the policy in the future.  But at this point in time the policy encourages users to purchase tools, put them to work under the users' unique situations and see in real life.  Festool must be comfortable with the good and bad that comes with having this policy and Shane has posted here that actually very few tools as a percentage of the total get returned.  I guess that Festool USA must be confident in their claims about their products and the way that they perform.

Here is the description of the warranty from the Festool USA website:

"Buy with confidence. If you are not completely satisfied, return your tool to the selling dealer within 30 days and you will receive a refund of either your purchase price or the lowest retail price at which the same item has been offered since your date of purchase. Freight charges are not refundable."

Peter

I think everyone knows what you meant though & deep down I think you probably do as well.  There was others that suggested  it but hey, it's nothing to do with me.  I just don't think that is a good way to do business.

Take full advantage eh !!