Replacing a Deck for B/C Class Rental: Trex or Wood?

[Patrick McGowen]

You don’t have to read all below to weigh in as it is kind of a ramble, my core question is: what to use for decks in rentals comparing wood (redwood for example) and Trex or similar plastic decking. Trex is a recycled plastic board that looks like wood. It is nicer looking, but more expensive. Kind of like putting granite countertops in a low end rental, probably not worth it. However, Trex saves cost of having to stain every year, and may last longer? I needed to make this decision fast and a quick search on Bigger Pockets did not yield much, in retrospect I think I made the wrong choice. Either way, I vowed once I got through the project, I would compile my costs and pose the question and try to get some discussion on it. Here is the full story.

(picture of old deck that needed replaced)

Replacing this deck pictured above has been on my to-do list since buying property a few years ago. My best guess is that it was built with the duplex originally in 1978. I didn’t bother maintaining (painting/staining) the last few years since I knew I would replace it soon, which probably caused decay to speed up. When I bought, I firmed up the stairs for safety and procrastinated. The latest tenants that moved in have a toddler, which brings up another issue; if you are paying close attention to the picture above, the railing is not up to code. It was go time to replace this deck and I needed to do it soon before the toddler jumped off the deck. Also, the tenants were going to be out of town for a few days and I wanted to take advantage of their absence and get it done.

Because of my hurry I did not exactly price out and compare alternatives, but had rough numbers. My real mistake was I did not take time to ponder and did not ask investor friends to compare the options with me. My rough math was that the maintenance costs of the next 20 years of re-staining the wood would pay for the extra up front costs of trex, and I would have a nicer deck for my tenants as a bonus. I had a quote from a contractor for redwood, then I asked a couple contractors and none had done trex before. I had installed trex on my own deck on our home, pictured below. Although it was low enough not to need a railing, so I have never installed the trex railing. Although you can see I still made a not-up-to-code kind of railing with benches. I think this bench would meet code for a higher deck if I had 2 or 3 times the bench brackets to bring the spacing to 4”. To meet the spacing so a kid won’t squeeze through.

(Pic of my home deck with trex, no railing. note this is our local investor meet up, we are in in depth wealth building discussion; Thanks Regena for the picture)

If I was going to make that much of an investment and do a quality trex material, I wanted to be sure it was installed right so I had to wait until I could do it myself (one of my problems, I feel I have to do everything myself even if it isn’t the highest and best use of my time).

So let’s compare cost and quality. Costs below are for materials only. If I were to factor in my own time and what I paid my kids to help me, probably figure 1-2k in labor also for either option. I considered separately costs for structure, decking, railing, and other; comparing wood and trex.

Structure costs include post footings, posts, beams, joists, stair stringers, all hangars/screws/nails (except the special deck brackets fasteners I included with decking). I spent $640 for the structure. This is probably the same for wood or trex. Although there could be some cost savings with wood. Trex decking is not quite the same structurally as redwood deck boards. I would guess structurally that 12 inch joist spacing with trex is equivalent to 16 inch joist spacing with redwood, or 16” spacing with trex boards is similar to 24” spacing with wood (note max recommended joist spacing for trex is 16 inches). So for trex add in a couple extra joists. I would have done three stair stringers either way, but similarly, I could have gotten away with one less stair stringer with redwood. So you could probably reduce structural material costs by about $50 for wood.

Redwood structure costs: 590

Trex structure costs: 640

Decking materials for trex are not bad. This deck is 16 feet long, so I used 16 foot boards, no cutting or ugly butt joints. Installation was a bit of a pain (will discuss screws vs hidden brackets further down). So labor was probably more on installing trex deck boards compared to installing wood, but considering no need for staining once built, probably equal labor costs. Decking was pretty straight forward 18 deck boards and fasteners

Redwood deck boards: 430

Trex deck boards: 900

One note on deck boards, I bought the cheaper trex boards and was told by guy at contractors desk that these ones had the slot in them for the deck brackets. They did not which meant I needed a router bit and a little extra labor to router a slot in the side of the board. You can attach trex decking with deck screws, but I do not recommend. The plastic does not compress the same as wood and even if you pre-drill, there creates kind of a bubble of plastic around the deck screw. I strongly recommend using the trex brackets/fasteners that attach to the side of the board and are pretty invisible. I still did deck screws on the outer board and stair treads. These hidden fasteners cost be about $100 compared to maybe $20 deck screws. I think if you are going to spend the extra for trex, go a little further in cost for the hidden fasteners (although a theme her is I kept adding to cost until in the end probably too much).

Railing is really the problem with trex. It is expensive and had to be special ordered. This was really the big cost. The nice thing is that you could mix and match colors. Keep in mind there are 4x4 treated wood posts in place for the railing to attach to that I included in my structure cost above. This is where I got kind of stupid, I kept telling myself, as long as I was going to do this I might as well do it right. Total cost for the railing system was 2740. I could have attached the trex railing to the 4x4 treated posts directly and could have reduced the cost by not using post sleeves ($840), post caps (110) and post skirts (60), but I convinced myself that as long as I was going to do this a little bit more to do it right would be okay. Also, I could have gone all white instead of picking colors. Estimate I got for all white was right around 2000 including the post coverings.

Trex railing all white: 2000

Trex railing cool colors 2740

Redwood railing 700

(pic of new deck)

My thoughts after installing the railing, I just do not think it is as sturdy or durable as wood. Fine for a high end home that is treated nicely, but it is certainly not industrial strength. The top and bottom rail are strong, and decently attached to the posts. Although one challenge is that you measure the rail, cut it, and when you attach, the attachment bracket sucks the post cover tight and you have a 1/8” gap in the railing at the post; structurally okay, but does not look as good. The real issue is how the spindles are attached to the railing, there is a plastic spacer that snaps in and holds them in place, I cracked this a few times installing.

(I will try to add a picture of the railing spacer later)

Other costs included dump fees for demo of old deck, a few tools I needed and some lattice. This was $290, and same for either material option except the $40 router bit for deck board attachment

Cost summary: Table below shows comparison. I recently paid $650 for a painter to stain a deck easily twice the size. Assuming this deck would cost about $400 to stain every other year, $200 per year maintenance cost for wood seems about right.

So bottom line, I spent almost $2,000 extra for reduced maintenance costs (about 7.5% return amortized over 20 years) and for a nicer looking deck, and then I spent another 700 for pretty colors on the railing. Railing durability is questionable.

Final product below (compare to the first picture). This particular deck is the upstairs unit. The downstairs unit had a concrete below grade patio under the deck. There is some metal flashing under the deck to drain water and not flood the patio. Also I need to separate the two yards (each unit of this duplex has their own yard), the deck is in the yard for the upper unit, and the patio underneath the deck leads out to the yard for the lower unit, so I need to separate the space; original builders used corrugated fiberglass. I thought lattice looked better. I did look at plastic lattice (similar to trex material), but it just seemed much more flimsy and weak and guaranteed to break and cause maintenance issues. Prices for plastic lattice and stained cedar were about the same.