It does tend to be a high effort, modest result thing, but if you're solarizing/smothering over the winter and into spring, that's going to be far more effective. Solarizing in September is no great shakes, even in CO, but smothering? Yeah, that works.

Half the time, we get people who want to solarize for 2 weeks in May and think that'll do it. Er, no. That's called "dormancy" to most lawns and most weeds think of it as a tropical vacation. :-)

Will this be 100% effective? No. Will you need to pull out some chemicals next spring? Probably, although you can certainly hand-weed. Will it be the amount you'd need to use if you didn't do this? Absolutely not, you'll definitely be ahead of the game in terms of using far less than otherwise. So I'm going to say go for it and that it's a win-win in terms of chemical savings and avoiding overmuch biting of bullets, which nobody likes.

If you're having the property box-bladed next spring to prep for the sod, you may be far enough along that you don't even need to use the chems at all. Check with your contractor, depending on the prep that needs to be done.

If you're doing it yourself, remember that sod needs really good soil contact and to be moist to damp (not wet, drenched, soaked, puddled, dry, strawlike, or parched) for the first two weeks, then gently backed off as it can handle it. You may already know that, but just in case, and pardon if I'm repeating what you already know. It's just that CO tends to go rather low humidity and dry and I remember seeing a lot of spring sod Go Wrong, so I'd rather avoid a posting next June other than, "Look at my great sod!"

Thank you so much for the quick reply! Good to hear I'm not barking up the wrong tree!

Yes, I am planning on doing the sod myself and have a moderate idea of the work and watering requirements but a reminder is always helpful!

Sheet composting can work- but tends to work better for an area that is planned to be worked/dug like a garden, because weeds still like to pop up in sheet composting and I think you are wanting a more full dead effect if possible.

Solarization works great to kill- best time for it is later winter into early fall when the clear plastic can really cook the dickens out of the space for several weeks. And since you live in a snow area, it covers the clear and is less potent through the winter. Solarization works best for me when the plastic is pinned on the edges but not really pinned down much in the middle.

Smothering with dark plastic or tarps from fall through to spring works best for this time of year in my experience. Killing with darkness as the fall plants and root systems need it, and keeping it covered in the earlier spring when new growth would need it. It is less thermally potent overall than using clear plastic, but during the winter you aren't going for heat like with what works with clear plastic during summer. Smothering has worked best for me when I've pinned down the edges and also try to weight down the top covering a bit to keep it as close to the ground as possible. I got a goodly handful of old wood boards I use for this.

So with all this info in mind, is there any issue laying my sheet compost down then covering with plastic to get the best of both worlds?

To make for a garden bed, not so much a problem to do both. But for sod? Since it's supposed to have really good contact with the soil, I would think that trying to place it over not fully composted into the soil lasagna would not work so swell.

Got it! My hope is that by the time I am ready for sod, the sheet will be broken down enough that I can rototill the area for good soil contact. Maybe I am hoping for too much

Rototilling for lawn installation is usually a Really Bad Idea--it leads to a bumpy lawn surface that never settles down correctly simply because it's not possible to assure that you rototill to the exact same depth everywhere and to the same consistency.

It's one of those things you'll never notice in a garden (although mixing soil horizons is never really a great idea and I'm personally not sure why people do it...this is another story, however...), but you'll notice it every time you run the (wheeled) lawnmower and bottom out and scalp this, or don't cut that...

If you do--and you actually can as long as you take the right steps afterward, then have the area professionally regraded and box-bladed. It's worth the time and money and will re-flatten the soil and fix the issues. Even so, you'll still notice minor annoying height differences, but those little ones will tend to even out over time and with, perhaps, a bit of added soil.

Dethatching and setting the tines a bit deep to scratch into the soil wouldn't be a problem, though. As long as the disturbance doesn't dig deep, you wouldn't have any issues with bumpiness.

Lol- you said the rototill word. That can bring forth hot debaters for and against that in general in gardening areas of the forums. Since I'm more of a gardener than a lawn person.. I'll let the much more expert lawn people around here tell you what's up or not with rototilling for sod and lawn prep.

Yep, that's a Bad Word with lawn people. :-) I have no objection in gardens, if you want to, great. If you'd rather not, great. Just be careful with the soil biology. I am Switzerland.

Most of us have done it once in lawns and have sworn off ever doing it again. I've even spent years correcting the box blade job done on this property when my husband and I bought it. It wasn't well-done, but far better than a home rototill job.