Loose lay vinyl flooring is a type of vinyl flooring that's installed without adhesive.  It's simply laid down on the subfloor and held in place by its own weight and, in some cases, perimeter weights or double-sided tape.  This contrasts with traditional glued-down or click-lock vinyl installations.

**Pros of Loose Lay Vinyl Flooring:**

* **Easy Installation:**  This is the biggest advantage.  Installation is significantly faster and easier than glued-down or click-lock vinyl, requiring minimal tools and expertise.  This translates to lower labor costs.
* **Water Resistant/Waterproof:**  Many loose lay vinyl options are water-resistant or waterproof, making them suitable for kitchens, bathrooms, and basements.  Spills are easier to clean up.
* **Comfortable Underfoot:**  The slight give underfoot can provide more comfort than rigid core flooring options.
* **Easy Removal & Replacement:**  If damaged, individual planks or tiles can be easily replaced without disturbing the rest of the floor.  The entire floor is also relatively easy to remove if needed.
* **Suitable for Uneven Subfloors:**  Loose lay vinyl can accommodate minor imperfections in the subfloor better than glued-down options, although significant leveling may still be necessary.
* **Sound Dampening:**  The loose lay nature can provide some level of sound dampening compared to hard flooring options.

**Cons of Loose Lay Vinyl Flooring:**

* **Potential for Movement:**  The flooring can shift or move over time, especially in high-traffic areas or with temperature fluctuations.  This can lead to gaps, ripples, or curling at the edges.  While perimeter weights can help, it's not foolproof.
* **Less Durable:**  Compared to glued-down vinyl, loose lay can be more susceptible to damage from heavy objects or sharp impacts.
* **Not Ideal for High-Traffic Areas:**  High traffic can increase the chances of shifting or damage.
* **Can be Tricky Around Edges:**  Achieving a neat and professional finish around edges and transitions can be more challenging.
* **May Not Be Suitable for All Subfloors:**  While it tolerates minor imperfections, extremely uneven or unsuitable subfloors may still require preparation.
* **Can Be More Expensive:**  While labor costs are lower, the material cost per square foot can sometimes be higher compared to other vinyl flooring types.

**Overall:**

Loose lay vinyl flooring is a good option for DIYers, renters, or those looking for a quick and easy flooring solution.  However, it's important to weigh the pros and cons carefully, considering your specific needs and the level of traffic the floor will experience.  If durability and absolute stability are paramount, glued-down or click-lock vinyl may be a better choice.