Building Materials
Buy and sell building materials in Guatemala.
Walls in most Guatemalan houses are block, tied together with reinforced concrete columns and bond beams, and the structural shell is bought in the units the trade uses: block by the hundred, rebar by the hundredweight, cement by the sack, sand and crushed gravel by the truckload. New material from block plants and builders’ merchants has a place here, and so does the surplus a finished build leaves behind, from a few hundred blocks to a stack of roofing sheet never put up. Before you load anything, two marks tell you what you are getting: the colour stamp on a block, and whether rod and sheet are full weight or light.
Block, rebar, cement and roofing sheet for the structural shell:
the grey stage of a house, before the walls are rendered, runs on those four. The 14 cm block is the ordinary wall and the 19 cm one goes where the plans ask for more; the U-shaped bond beam block is where the beam is cast, and pumice block is the lighter option. Rod here means corrugated rebar, bought by the length or by the hundredweight. Roofing sheet is galvanised or aluzinc and sold by its length in feet. Rod cutters and benders are under tools, and the barrows and hand trucks that move sacks across a site under wheelbarrows and carts.
The blue, red or green stamp on a block:
block made to the Guatemalan standard is painted with the colour of its class, blue for A, red for B and green for C. Class A carries the most load and absorbs the least water; C is the weakest. The class a wall needs is written on its structural plans, so compare blue-stamped prices with each other, not with an unmarked pile. Block from a plant comes with a delivery slip giving the class, production date and lot, so ask whether the seller kept it. An unstamped block is a guess, whatever it weighs.
Full-weight and light rod, and the same split in roofing sheet:
full-weight rod carries the whole steel section of its size, comes in grade 40 or 60 and has size and grade rolled into the ribs. Light rod is thinner than its label. It will do for a window grille or a fence, never for a column, a bond beam or a footing. Counting is the quick test: a hundredweight of full-weight 3/8″ is about thirteen lengths, so a bundle that counts out several more is lighter bar. Roofing sheet splits the same way: full-gauge sheet keeps the thickness its gauge number promises, and a 26 is stiffer than a 28 between widely spaced purlins.
What surplus block and rod fetch against new:
new 14 cm block is around Q450 a hundred, and 3/8″ rod about Q30 a length at full weight against a little over Q20 for light bar. Per length that saving is small, and a column is the wrong place to make it. Neither block nor rod wears out in a pile, so clean, stamped surplus sells close to new, less the freight the buyer pays to collect it. The real discounts are on material that has already worked: sheet taken down from a roof, or block salvaged from a demolished wall with mortar still on its faces.
Cement sacks, block faces and sheet that has been on a roof:
cement starts to set once damp reaches it. Press the sack: it should give like flour, and hard lumps mean it is finished. Read the printed date too. On block, look for whole corners and webs and a face that does not crumble when you scratch it with a key. A light orange bloom on rod is harmless; flaking scale and pitting are not, and a bar that has been bent and straightened again should stay out of anything structural. Used sheet shows its age at the nail holes, along the laps and at the cut ends, which is where rust starts.
A surplus pile for sale: the count, the stamp and the truck:
count it in its unit: how many blocks, of which width and stamp colour; how many lengths of rod, of which size and grade, and whether they are full weight; how many sacks and their date; how many sheets, of which length and gauge. Photograph the stamp, the marks on a rod end and the pile, and say whether it was kept under a roof or out in the open. Ladders and frames from the same job go under stairs and scaffolding. Then describe the access, because a buyer in Santa Cruz del Quiché or Puerto Barrios costs the truck before the block: whether a loaded truck reaches the pile, how far is carried by hand, and whether you help load.