Thatching serves as a waterproof roofing material in many parts of the world. Whether in use as a tropical structure roof or a decorative roof for a backyard tiki hut, properly thatched roofing is lightweight, rain resistant and can be very inexpensive if you have the material already growing nearby. Key to thatching is proper use of battens or the crosswise supports that support the thatch. If you have a tiki hut or tropical hut to cover, give this thatching method a try.
Collect the grass or reeds by cutting through the stem above the ground about 2 inches to 3 inches. This gives a long length to the material and sturdy stem without getting root material.
Spread layers of the grass or reeds about 1-inch thick across the lowest batten. You will work from the bottom up, so the layers nearest the peak are on top of the thatch and water runs down.
Use one of two methods to attach the thatch to the batten. Take small bundles about 1 inch in diameter and roll the top end over the batten towards the back, and down. Make a loop with the grass or reeds over the batten, then tie off the bundle at the bottom of the loop below the batten with the bark string or hemp. The second method is to lay a 1-inch thick layer of reeds or grass across a section of batten. Lay another batten over the top of the section, and secure the battens together at both ends.
Move across from corner to corner until the bottom layer is thatched, then move up a layer and go back across from corner to corner again, overlapping the bottom ends of the second layer over the top of the first, or bottom layer. Overlap each layer by about half of the length of the thatch material you are using.
Gather the palm leaves with the stem intact.
Attach long-stemmed palm leaves by stick thatching. Tuck the end of the stem beneath the batten and slide upward. Tip the stem over the batten above the layer you are working on, so it pins the frond in place. Create the first row in this manner. Trim the stems to a uniform length, rising no more than 1 inch to 2 inches above the batten. The second row, use the same technique, but place your new fronds between the stems that are resting on the second row batten, overlapping the fronds below. Continue with all layers this way, corner to corner, bottom to top.
Split the stalks of long palm leaves and bind the two halves of the stalk together so the leaf is now a double layer. Lay the leaf on the vertical supports so the batten supports the lower edge of the leaf and secure the stalk to the vertical supports. Continue across with a good overlap on each layer, bottom to top as before.