Are you considering rebuilding your deck the composite decking?  Here are some things to consider before you commit to this relatively new material.

I recently was on a home inspection for a home that was approximately 10 years old.  During the inspection I was looking at 2 decks that were part of the home.  These decks were constructed of a composite wood material that has become popularized as a maintenance free alternative to wood.  We had come across several issues during the inspection of the deck. One issue of note was that the boards where cracking and splitting along the edges.  I attribute this to spacing.  Like most decking wood or composite there needs to be some space for expansion and contraction.  The other issue that we noted was the deterioration of the wood joists under the composite decking.  This was due to the drying qualities of composite decking. Wood decking will absorb moisture and release to the air around it. Composite decking does not absorb water.  Moisture that gets trapped under the decking and on top of the wood joists would tend to stay there and keep the joist from drying properly.  Wood that is not allowed to dry properly will be more susceptible to rot and decay. 

Here are some other common issues with composite decking.

Cost:  Compared to traditional wood decking ($15/ sq. ft.), composite decking is considerably more expensive ($30-$36/ sq. ft.).  This cost is for materials.  The labor cost tends to be a bit higher due to additional steps that are required during installation.  Composite decking requires the joist to be closer together then that of traditional wood. If the composite lumber is not properly supported it tends to bow and warp.  Each board must be pre-drilled during the fastening process.  These add to the cost of materials and additional labor times.

Read the rest of Jason's article here  http://newtown.patch.com/groups/jason-horns-blog/p/bp–some-issues-with-composite-decking